Advances in Oral Drug Delivery Systems: Challenges and Opportunities

Comparative stabilization mechanism of self-assembling fattigated gelatin, micellar polyethylene glycol hexadecyl ether, and electrostatic interactive xanthan gum for aqueous labile decitabine

Decitabine (DCB) is very unstable in aqueous solutions because of the opening of the N-5 and C-6 aza-ring. The objective of this study was to investigate a stabilization mechanism of aqueous-labile decitabine (DCB) with three different materials by preparing binary spray dried powders (SDs): self-assembling fattigated gelatin-oleic acid conjugate (GOC), micellar polyethylene glycol hexadecyl ether (Brij® 58), nonionic surfactant and electrostatically interactive xanthan gum (XA), an anionic polysaccharide. GOC was synthesized by covalently conjugating oleic acid with gelatin. The degradation rate of intact DCB was highly dependent on the solution conditions, showing stability in the following decreasing order: pH 1.2 < pH 4.5 < pH 6.8 < pH 7.4 < deionized water (DW) < 50 % ethanol. DCB was the most unstable in the low pH 1.2 solution, with only 25.1 % remaining after 2 h. As the GOC content (DCB: GOC = 1:5, 1:10, 1:50) increased in the GOC SDs, the degradation rate of DCB decreased proportionally because GOC readily formed nanoparticles (NPs) with a critical micelle concentration (CMC) of 0.0416 mg/mL to protect DCB against degradation. This nano-forming behaviors of GOC was also visualized using field emission transmission electron microscope (FE-TEM) and field emission scanning electron microscope (FE-SEM). Brij® 58 SD (DCB: Brij® 58 = 1:10) slightly increased the DCB stability via micellization above CMC for a short period of time as compared to the DCB control. In contrast, XA had more favorable stabilizing effect at a low pH 4.5 solution via polyelectrolyte complex formation of positively charged DCB and negatively charged XA compared with other XA SD prepared in DW or pH 6.8 solution. Among the three stabilizing materials, GOC provided the highest stabilization capacity via the nanonization process compared with micellar Brij® 58 and electrostatically interactive XA. Furthermore, the molecular hydrogen bonding interactions and amorphousness of DCB with GOC, Brij® 58, and XA contributed to the stabilization of DCB according to instrumental analyses such as Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC). The in vitro release of GOC SDs was maintained at pH 1.2 and pH 6.8, while DCB alone was rapidly released and then degraded. The more GOC used, the more DCB release delayed. The release rate of Brij® 58 SD was released immediately but gradually decreased. However, XA SD also rapidly released DCB, which then degraded in a steeper manner. The release profiles of DCB were governed by the balanced effect of the stabilization capacity in the solution and loading contents of three stabilizing materials in SDs formulations.

Single-dose oral administration of drug-loaded magnetic 3D-printed microbullets for eradication of Helicobacter pylori

Infections of Helicobacter pylori (H. pylori) affect 42.1 % of the Chinese population and 43.1 % of the world population. H. pylori inhabits the mucous sublayer at the pylorus, leading to gastric ulcers, gastritis, and even cancer. Oral antibiotics are usually used to treat H. pylori infections, whereas traditional quadruple therapy has side effects including headaches, nausea, diarrhea, intestinal dysbacteriosis, antibiotic resistance, and repeat infections. Here, a drug-loaded magnetic microbullet was designed to realize long-term retention in the stomach for one-shot treatment for H. pylori infections. It comprises a hollow cylinder wherein eight microneedles homogenously distribute at the top and several round pores located at the bottom. It was three-dimensional (3D)-printed by stereolithography. A clarithromycin (CAM) ground mixture (CGM) was prepared to improve solubility. Enough CGM powders were filled into the cylinder, covered by a small round magnet, and sealed to form a CAM-loaded magnetic microbullet (CMMB). CAM continually released from CMMBs for >24 h. With outside magnetic guidance, an oral CMMB targeted the pylorus site and the microneedles immediately headed into the mucosa followed by long-term local drug release. The in vitro and in vivo safety of CMMBs was confirmed, where their swelling rates were low, and the oral CMMB was finally completely evacuated. An oral CMMB was administered to H. pylori-infected mice and maintained in the stomach for 36 h with magnetic guidance, and the successful eradication of H. pylori was confirmed after single-dose administration. Oral CMMBs are a convenient medication for the eradication of H. pylori.

Nanoemulsion and nanoemulgel-based carriers as advanced delivery tools for the treatment of oral diseases

Oral diseases rank among the most widespread ailments worldwide posing significant global health and economic challenges affecting around 3.5 billion people, impacting the quality of life for affected individuals. Dental caries, periodontal disease, bacterial and fungal infections, tooth loss and oral malignancies are among the most prevalent global clinical disorders contributing to oral health burden. Traditional treatments for oral diseases often face challenges such as poor drug bioavailability, breakdown of medication in saliva, inconsistent antibiotic levels at the site of periodontal infection as well as higher side effects. However, the emergence of nanoemulgel (NEG) as an innovative drug delivery system offers promising solutions where NEG combines the advantages of both nanoemulsions (NEs) and hydrogels providing improved drug solubility, stability, and targeted delivery. Due to their minuscule size and ability to control drug release, NEGs hold promise for improving treatment of oral diseases, where versatility of these delivery systems makes them suitable for various applications, including topical delivery in dentistry. This review concisely outlines the anatomy of the oral environment and investigates the therapeutic potential of NE-based gels in oral disorder treatment. It thoroughly examines the challenges of drug delivery in the oral cavity and proposes strategies to improve therapeutic efficacy, drawing attention to previous research reports for comparison. Through comprehensive analysis, the review highlights the promising role of NEGs as a novel therapeutic approach for oral health management via research advancements and their clinical translation. Additionally, it provides valuable insights into future research directions and development opportunities in this area.

Optimising distribution of hollow microneedle in arrays for transdermal drug delivery considering effects of tissue compression on drug permeability

Hollow microneedles (HMNs) are advanced transdermal drug delivery (TDD) devices that can create micro-perforations in the skin, enabling high molecular weight drugs to bypass the resistance of the skin's top layer, the stratum corneum. These MNs have been shown to enhance drug permeability K in skin with minimal or no discomfort. It is recognised that the variability and interplay of different MN parameters, including the MN distribution within an array, can significantly influence the HMN-based TDD rate. However, optimising these parameters can achieve consistent MN performance. In recognising this, our paper aims to develop a theoretical framework for optimising the HMN distribution in the arrays. The methodology involves formulating an optimisation function g based on different geometrical and physical properties of the MN and skin and associating this with the skin permeability (K) of drugs delivered via the HMNs. The methodology has been established to quantitatively assess the impact of MN design parameters on drug diffusion through the skin, including the effects of compressive strain caused by HMN insertion. The studyshows that an elevated value of g is associated with increased drug K in the skin. The results from the established framework have enabled us to determine the optimal design for various HMN configurations. The data generated from this optimisation technique is subsequently utilised to estimate the skin K of several high molecular weight drugs delivered through an HMN system.

Recent advances in functional lipid-based nanomedicines as drug carriers for organ-specific delivery

Lipid-based nanoparticles have emerged as promising drug delivery systems for a wide range of therapeutic agents, including plasmids, mRNA, and proteins. However, these nanoparticles still encounter various challenges in drug delivery, including drug leakage, poor solubility, and inadequate target specificity. In this comprehensive review, we present an in-depth investigation of four distinct drug delivery methods: liposomes, lipid nanoparticle formulations, solid lipid nanoparticles, and nanoemulsions. Moreover, we explore recent advances in lipid-based nanomedicines (LBNs) for organ-specific delivery, employing ligand-functionalized particles that specifically target receptors in desired organs. Through this strategy, LBNs enable direct and efficient drug delivery to the intended organs, leading to superior DNA or mRNA expression outcomes compared to conventional approaches. Importantly, the development of novel ligands and their judicious combination holds promise for minimizing the side effects associated with nonspecific drug delivery. By leveraging the unique properties of lipid-based nanoparticles and optimizing their design, researchers can overcome the limitations associated with current drug delivery systems. In this review, we aim to provide valuable insights into the advancements, challenges, and future directions of lipid-based nanoparticles in the field of drug delivery, paving the way for enhanced therapeutic strategies with improved efficacy and reduced adverse effects.

Longan-inspired chitosan-pectin core-shell hydrogel beads for oral delivery of biodrugs to enhance osteoporosis therapy

Osteoporosis, a common disorder, is characterized by a systemic reduction in bone mass and structural integrity, resulting in brittle bones. Reducing bone loss and enhancing bone density through oral administration of biopharmaceuticals provides significant advantages, including convenience and non-invasiveness for patients. However, challenges such as poor absorption and enzymatic degradation necessitate the development of innovative drug delivery systems. This research introduces a core-shell hydrogel system inspired by the natural architecture of Longan fruit, constructed from pectin and chitosan biopolymers, designed to create biocapsules and sustain the release of biodrugs. In this system, salmon calcitonin (sCT) was encapsulated within mesoporous silica nanoparticles (MSNs) and incorporated into the core of the beads. The synthesis of the core-shell hydrogel beads was carefully regulated by adjusting the immersion time and concentration of the crosslinker. The hydrogel beads demonstrated durability, with the pectin shell effectively preventing rapid degradation in the stomach, while the chitosan layer enhanced adhesion to the intestinal walls, safeguarded sCT, and enabled sustained drug release over an extended period of up to 30 h. Furthermore, biocompatibility tests indicated minimal cytotoxicity and hemolysis. Cellular uptake assays demonstrated that the core-shell beads effectively encapsulated sCT and ensured its prolonged release to CT-26 cells. This study presents a promising platform for oral sCT delivery, offering enhanced efficacy, patient compliance, and a potential replacement for injection-based therapies.

Targeting Neuroinflammation in Central Nervous System Diseases by Oral Delivery of Lipid Nanoparticles

Neuroinflammation within the central nervous system (CNS) is a primary characteristic of CNS diseases, such as Parkinson's disease, Alzheimer's disease (AD), amyotrophic lateral sclerosis, and mental disorders. The excessive activation of immune cells results in the massive release of pro-inflammatory cytokines, which subsequently induce neuronal death and accelerate the progression of neurodegeneration. Therefore, mitigating excessive neuroinflammation has emerged as a promising strategy for the treatment of CNS diseases. Despite advancements in drug discovery and the development of novel therapeutics, the effective delivery of these agents to the CNS remains a serious challenge due to the restrictive nature of the blood-brain barrier (BBB). This underscores the need to develop a novel drug delivery system. Recent studies have identified oral lipid nanoparticles (LNPs) as a promising approach to efficiently deliver drugs across the BBB and treat neurological diseases. This review aims to comprehensively summarize the recent advancements in the development of LNPs designed for the controlled delivery and therapeutic modulation of CNS diseases through oral administration. Furthermore, this review addresses the mechanisms by which these LNPs overcome biological barriers and evaluate their clinical implications and therapeutic efficacy in the context of oral drug delivery systems. Specifically, it focuses on LNP formulations that facilitate oral administration, exploring their potential to enhance bioavailability, improve targeting precision, and alleviate or manage the symptoms associated with a range of CNS diseases.

Harnessing the Potential of Human Breast Milk to Boost Intestinal Permeability for Nanoparticles and Macromolecules

The intricate interplay between human breast milk, nanoparticles, and macromolecules holds promise for innovative nutritional delivery strategies. Compared to bovine milk and infant formula, this study explores human breast milk's role in modulating intestinal permeability and its impact on nanoparticle and macromolecule transport. Comparative analysis with bovine milk and infant formula reveals significant elevations in permeability with human breast milk, accompanied by a decrease in transepithelial electrical resistance, suggesting enhanced paracellular transport. Mechanistically, human breast milk reduces Zonula occludens-1 levels, suggesting a regulatory role in intestinal barrier function. Through in vitro and ex vivo evaluations, we aim to understand better the mechanisms behind enhanced permeability and how human breast milk affects nanoparticle physicochemical properties, potentially modulating their behavior. Specifically, human breast milk improves the intestinal permeability of liposomes in a porcine intestinal model, with associated changes in the composition of milk proteins corona related to liposome charge. These findings underscore the unexploited potential of human breast milk in facilitating transport across the intestinal barrier, offering novel avenues for human nutritional delivery and therapeutic interventions.

The Pharmaceutical and Pharmacological Potential Applications of Bilosomes as Nanocarriers for Drug Delivery

Nano-drug delivery systems provide targeted solutions for addressing various drug delivery challenges, leveraging nanotechnology to enhance drug solubility and permeability. Liposomes, explored for several decades, face hurdles, especially in oral delivery. Bile-acid stabilized vesicles (bilosomes) are flexible lipid vesicles, composed of phospholipids or other surfactants, along with amphiphilic bile salts, and they show superior stability and pharmacokinetic behavior in comparison to conventional vesicular systems (liposomes and niosomes). Bilosomes enhance skin penetration, fluidize the stratum corneum, and improve drug stability. In oral applications, bilosomes overcome drawbacks, offering improved bioavailability, controlled release, and reduced side effects. Vaccines using bilosomes demonstrate efficacy, and bilosomes for intranasal, inhalation, ocular, and buccal applications enhance drug delivery, offering targeted, efficient, and controlled activities. Formulations vary based on active substances and optimization techniques, showcasing the versatility and potential of bilosomes across diverse drug delivery routes. Therefore, the aim of this comprehensive review was to critically explore the state-of-the-art of bilosomes in drug delivery and potential therapeutic applications.

Use of pH-sensitive microcapsules for selective delivery of nanozymes and biological enzymes in small intestine

Unlike the intravenous route, oral delivery systems face challenges due to an acidic gastric environment, which can degrade or inactivate therapeutic compounds before they reach the small intestine (SI). Therefore, developing oral delivery strategies that protect cargo from acidic environments and release the content in the SI is imperative. Herein, a novel approach utilizes the pH-sensitivity of alginate-based microcapsules that degrade and release the contents at pH ≥ 7.0. The microcapsules were used to encapsulate gold nanoparticles (AuNPs, a model nanozyme) of varying sizes (2, 15, and 70 nm) and horseradish peroxidase (HRP, a model enzyme). The AuNPs- and HRP-loaded microcapsules (AuNPs-MCap and HRP-PEG MCap) were unaffected at acidic pH (2.0-6.0), as the intrinsic structure and properties of encapsulated AuNPs and HRP were intact. The microcapsules rapidly released the encapsulated AuNPs and HRP at pH ≥ 7.0. In vivo, oral administration of AuNPs-MCap and HRP-PEG MCap to Wistar rats also showed significantly enhanced absorption of AuNPs and HRP in SI, leading to higher concentrations in blood than in their corresponding unencapsulated forms. Overall, the results underscore the potential of pH-responsive microcapsules for protecting pH-sensitive nanozymes, biological enzymes and other bioactive compounds from the acidic gastric environment and for effective and targeted delivery to the SI.

An Overview on the Role of Ionic Liquids and Deep Eutectic Solvents in Oral Pharmaceuticals

Over the past twenty years, ionic liquids (ILs) and deep eutectic solvents (DESs) have gained recognition across various fields, including catalysis, extraction and purification, materials science, and biotechnology. Notably, the use of ILs and DESs in pharmaceutical research, especially in drug delivery, has seen remarkable expansion over the past decade. This review offers a comprehensive analysis of ILs and DESs specifically designed for the oral administration of drugs having unfavorable biopharmaceutical properties. The classification and characteristics of ILs and DESs, along with their newer natural (Bio-ILs and NaDESs) and therapeutic subcategories (API-ILs and TheDESs) are outlined. Additionally, a further subgroup of ILs, known as surface active ionic liquids (SAILs), is described. Then, a detailed examination of the available manufacturing methods in a sustainable, time-consuming, and scalable perspective, and toxicity concerns in relation to their subdivision are evaluated. Finally, their specific applications in oral drug delivery, whether used as neat solvents or converted into administrable dosage forms, are analyzed and discussed. Despite the significant advancements in recent years regarding the use of these solvents in oral drug delivery, there are still many aspects that need further investigation. These include their interaction with biological systems (gastrointestinal fluids and mucosa), their long-term stability, and the development of effective drug delivery systems.

pH-Dependent Drug Delivery Systems for Ulcerative Colitis Treatment

Inflammatory bowel diseases (IBDs), such as ulcerative colitis (UC) or Crohn's disease, are becoming a growing global problem due to the limitations of current treatments, which fail to address the needs of patients effectively. UC is characterized by the widespread inflammation of the mucosal lining, affecting both the rectum and the entire length of the colon. Over the past forty years, traditional treatments for IBDs have primarily relied on anti-inflammatory drugs and immunosuppressive medications. Treatment could be more effective if drugs could be specifically targeted to act directly on the colon. Conventional drug delivery systems for IBDs encounter numerous challenges on their way to the colon, such as physiological barriers and disease severity. To address these issues, pH-dependent carriers have emerged as a promising advancement, offering a more effective and tolerable treatment for UC. These carriers enable localized, targeted action, reducing side effects and preventing the premature clearance of drugs from inflamed colon tissues. pH-responsive systems are a leading approach for targeted drug release in colitis treatment as they take advantage of the varying pH levels throughout the gastrointestinal tract (GIT). By incorporating pH-sensitive polymers, they ensure drug protection and controlled release in the lower GIT. This review will discuss the advantages and limitations of pH-dependent drug delivery systems for colon-targeted drug delivery.

Emerging Delivery Systems for Enabling Precision Nucleic Acid Therapeutics

Nucleic acid therapeutics represent a highly promising treatment approach in modern medicine, treating diseases at the genetic level. However, these therapeutics face numerous challenges in practical applications, particularly regarding their stability, effectiveness, cellular uptake efficiency, and limitations in delivering them specifically to target tissues. To overcome these obstacles, researchers have developed various innovative delivery systems, including viral vectors, lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, protein carriers, exosomes, antibody oligonucleotide conjugates, and DNA nanostructure-based delivery systems. These systems enhance the therapeutic efficacy of nucleic acid drugs by improving their stability, targeting specificity, and half-life in vivo. In this review, we systematically discuss different types of nucleic acid drugs, analyze the major barriers encountered in their delivery, and summarize the current research progress in emerging delivery systems. We also highlight the latest advancements in the application of these systems for treating genetic diseases, infectious diseases, cancer, brain diseases, and wound healing. This review aims to provide a comprehensive overview of nucleic acid drug delivery systems' current status and future directions by integrating the latest advancements in nanotechnology, biomaterials science, and gene editing technologies, emphasizing their transformative potential in precision medicine.

Glucuronidation of orally administered drugs and the value of nanocarriers in strategies for its overcome

The gastrointestinal tract (GIT) plays a pivotal role in the absorption of orally administered drugs, with the small intestine serving as the primary site due to its extensive surface area and specialized cell types, including enterocytes and M cells. After oral administration, drugs are generally transported via the portal vein to the liver, where they undergo first-pass metabolism. This process involves various enzymatic reactions, including glucuronidation, facilitated by uridine diphosphate-glucuronosyltransferase (UGT), a major phase 2 reaction in mammalian metabolism. UGTs conjugate glucuronic acid to a wide array of endogenous and exogenous substrates, enhancing their solubility and excretion, but significantly affecting the bioavailability and therapeutic efficacy of drugs. UGT enzymes are ubiquitously distributed across tissues, prominently in the liver, but also in the GIT, kidneys, brain, and other organs where they play crucial roles in xenobiotic metabolism. Species-specific differences in UGT expression and activity impact the selection of animal models for pharmacological studies. Various experimental models - ranging from computational simulations (in silico) to laboratory experiments (in vitro) and animal studies (in vivo) - are employed throughout drug discovery and development to evaluate drug metabolism, including UGT activity. Effective strategies to counter pre-systemic metabolism are critical for improving drug bioavailability. This review explores several approaches including prodrugs, co-administration of specific molecules or use of inhibiting excipients in formulations. Strategies incorporating these excipients in nanoformulations demonstrate notable increases in drug absorption and bioavailability. This review highlights the importance of targeted delivery systems and excipient selection in overcoming metabolic barriers, aiming to optimize drug efficacy and patient outcomes.

Preparation and evaluation of oral insulin nanocapsule delivery systems

Insulin therapy is essential for regulating blood sugar levels. Conventional subcutaneous injection is prone to psychological stress, local tissue damage and severe blood glucose fluctuations, and thus the development of oral insulin technology has become an alternative therapy. However, oral insulin faces challenges such as difficult absorption, poor adhesion, low bioavailability, and short duration of action, due to the large molecular weight, low permeability, and easily degradable by enzymes and gastric acids. In this study, oral insulin nanocapsule delivery systems (Orl-Ins-NPs) were developed by using polylactic acid-co-glycolic acid (PLGA) as the encapsulation material for insulin loading. After preparation, optimization and characterization, the mean size of Orl-Ins-NPs was 140.08 nm, the encapsulation efficiency of the system was 54.3 %, and the loading capacity of insulin was 2.2 %. In addition, cationic modification with chitosan/ polyethyleneimine promoted adhesion and permeation of the intestinal mucus layer, and surface coating with pH-responsive methyl methacrylate trimethylamine ethyl chloride copolymer achieved 100 % gastric protection. The results of rat blood glucose test showed that, subcutaneous injection of the control group reduced blood glucose concentrations within 1 h and returned to initial levels within 4 h, while Orl-Ins-NPs slowly reduced blood glucose concentration to 51.3 % of the initial level and maintains stability within 10 h. Orl-Ins-NPs exhibited good physicochemical stabilities, sustained release property, improved in vitro acid resistance, as well as long-term in vivo hypoglycemic effect. This system demonstrates its potential clinical application in oral insulin and other protein drugs delivery.

Microfluidics-on-a-chip for designing celecoxib-based amorphous solid dispersions: when the process shapes the product

The fundamental idea underlying the use of amorphous solid dispersions (ASDs) is to make the most of the solubility advantage of the amorphous form of a drug. However, the drug stability becomes compromised due to the higher free energy and disorder of molecular packing in the amorphous phase, leading to crystallization. Polymers are used as a matrix to form a stable homogeneous amorphous system to overcome the stability concern. The present work aims to design ASD-based formulations under the umbrella of quality by design principles for improving oral drug bioavailability, using celecoxib (CXB) as a model drug. ASDs were prepared from selected polymers and tested both individually and in combinations, using various manufacturing techniques: high-shear homogenization, high-pressure homogenization, microfluidics-on-a-chip, and spray drying. The resulting dispersions were further optimized, resorting to a 32 full-factorial design, considering the drug:polymers ratio and the total solid content as variables. The formulated products were evaluated regarding analytical centrifugation and the influence of the different polymers on the intrinsic dissolution rate of the CXB-ASDs. Microfluidics-on-a-chip led to the amorphous status of the formulation. The in vitro evaluation demonstrated a remarkable 26-fold enhancement in the intrinsic dissolution rate, and the translation of this formulation into tablets as the final dosage form is consistent with the observed performance enhancement. These findings are supported by ex vivo assays, which exhibited a two-fold increase in permeability compared to pure CXB. This study tackles the bioavailability hurdles encountered with diverse active compounds, offering insights into the development of more effective drug delivery platforms.

Oral delivery of protein and peptide therapeutics

Oral administration of proteins and peptides has gained significant attention recently due to its potential to transform therapeutic strategies, providing a non-invasive and patient-friendly method for delivering biopharmaceuticals. The primary hurdle in oral delivery stems from the harsh conditions of the gastrointestinal (GI) tract, characterized by acidic pH, enzymatic degradation, and limited permeability across the intestinal epithelium. Various innovative approaches have emerged to overcome these challenges, including nanoparticle-based delivery systems, mucoadhesive formulations, and chemical modifications of peptides aimed at improving stability and absorption rates. Nanoparticle-based delivery systems, such as liposomes, polymeric nanoparticles, and solid lipid nanoparticles, hold promise in protecting proteins and peptides from enzymatic degradation while enhancing their bioavailability. These nanoparticles can be tailored to target specific areas within the GI tract, extending drug release and enhancing therapeutic effectiveness. Mucoadhesive formulations utilize polymers like chitosan, alginate, and polyethylene glycol (PEG) derivatives to adhere to GI mucosal surfaces, prolonging residence time and facilitating drug absorption. Chemical modifications, such as PEGylation, glycosylation, and lipidation have been employed to enhance the stability and permeability of proteins and peptides in the GI tract. PEGylation, in particular, has been widely used to extend the circulation half-life and reduce the immunogenicity of therapeutic proteins. Advancements in nanotechnology, especially the development of smart nanocarriers capable of responsive drug release triggered by pH or enzymatic stimuli, show promise in further improving oral delivery of proteins and peptides. The integration of bioinformatics and computational modeling techniques has facilitated the design of novel drug delivery systems with optimized pharmacokinetic profiles. This chapter focuses on the advancements and challenges in the oral delivery of protein and peptide-based drugs, highlighting the innovative strategies being explored to enhance therapeutic outcomes.

Advanced polymeric systems for colon drug delivery: from experimental models to market applications

In recent years, nano and micro drug delivery systems targeting the colon have gained more attention due to increasing interest in treating colon diseases such as colorectal cancer and inflammatory bowel disease, i.e., Crohn's disease and ulcerative colitis. Usually, nanocarriers are exploited for their enhanced permeability properties, allowing higher penetration effects and bioavailability, while microcarriers are primarily used for localized and sustained release. In bowel diseases, carriers must go into a delicate environment with a strict balance of gut bacteria (e.g., colon), and natural or biodegradable polymers capable of ensuring lower toxicity are preferred. However, these systems are primarily delivered orally, so the carrier must go through the whole gastrointestinal tract, where it encounters significant pH fluctuations, different mucus layers, several enzymes, and a long transit time. For this reason, various approaches have been explored and evaluated, especially using pH-responsive and time-dependent systems. This review provides an overview of the contemporary methodologies employed in orally administered nano- and microparticles for colon delivery, encompassing both in vivo and in vitro investigations. It evaluates their strengths, weaknesses, constraints, and potential enhancements, leveraging mathematical and microfluidic models. Furthermore, it focuses explicitly on systems that have already reached the market and are presently employed in treating severe colon diseases.

Bioavailability Enhancement and Formulation Technologies of Oral Mucosal Dosage Forms: A Review

The oral mucosa is a versatile surface for drug administration, supporting both local and systemic therapies. Many active substances are effectively absorbed in the oral cavity, offering an alternative to enteral administration by bypassing the harsh gastrointestinal environment and hepatic first-pass metabolism. This has made oral mucosal drug delivery a growing area of research. Enhancing the bioavailability of active ingredients is a key focus in pharmaceutical technology, especially given the challenges of developing new drugs. Numerous strategies to improve bioavailability are compatible with oral mucosal delivery, with the unique anatomy of the oral cavity enabling specialized applications. A variety of dosage forms tailored for oral mucosal delivery meet therapeutic needs while addressing biopharmaceutical and patient compliance challenges. Proper formulation can achieve controlled release, improved bioavailability, and patient convenience. This review highlights the potential of oral mucosal drug delivery, focusing on bioavailability enhancement methods and the types and production technologies of dosage forms optimized for use in the oral cavity.

Transethosomes: A Comprehensive Review of Ultra-Deformable Vesicular Systems for Enhanced Transdermal Drug Delivery

The transdermal route is one of the effective routes for delivering drugs. It also overcomes many limitations associated with oral delivery. One of the limitations of this route is the drug's poor skin permeability-stratum corneum, the skin's outermost layer that also acts as a barrier for the drug to penetrate. Traditional liposomal formulation is utilized to overcome these limitations. However, these liposomes also have certain difficulty in delivering drugs across the barriers. Ultra-deformable vesicles are novel vesicular structures that are flexible and stable, they can easily bypass the skin barriers more efficiently and thus enhance bioavailability. These vesicles consist of ethosomes, transethosomes, and transferosomes. Transethosomes are more advanced than other vesicular systems because they contain ethanol, phospholipids, and edge activators, making them more deformable and easier to penetrate deeper skin membranes. These vesicular systems can be prepared by various methods, such as cold, hot, and thin film hydration. Characterization of transethosomes includes vesicular size, zeta potential, polydispersity index and encapsulation efficiency, stability, and drug release studies. These vesicular systems can be utilized to deliver a variety of medications transdermally, including analgesics, antibiotics, and arthritis medications. Despite their promising potential, ethanol-based formulations present several problems requiring additional study. This review aims to describe various vesicular structures that have been used to overcome the barrier for the transdermal delivery of drugs and also describe brief composition, method of preparation, characterization, mechanism of penetration of transethosomes, as well as highlighted various applications of transethosomes in medicine, clinical trials and patents.

Designing & optimisation of dual Ca2+ and SO42- ionic cross-linked sericin/pectin microbeads using response surface methodology for colon-specific delivery

Ulcerative colitis, a chronic inflammatory condition of the colon, requires precise and targeted treatment, and polysaccharides, with their pH responsiveness and biodegradability, offer an innovative approach for colon-specific drug delivery. This study aims to develop a highly precise drug delivery system with enhanced therapeutic and targeting efficiency for ulcerative colitis, focusing on the preparation, optimisation, and evaluation of dual cross-linked mesalamine-loaded sericin-pectin (DCLSPs) micro-beads. These beads utilise the pH-responsive and microflora biodegradability properties of polysaccharides for targeted colon delivery, employing the Response Surface Methodology. Formulated via the ionotropic gelation method with divalent cross-linking ions (Ca2+ and SO42-), the DCLSPs were optimised using a Box-Behnken design to assess the impact of the varying drug, pectin, and sericin polymer proportions. The DCLSPs were evaluated for entrapment efficiency, thermal behaviour, surface morphology, water uptake, swelling, and in-vitro drug release. Results indicated that spherical beads were successfully developed, with encapsulation efficiency ranging from 65.1% to 95.5%, drug loading between 32.5% and 49.9%, bead sizes of 0.75 mm to 0.92 mm, and degrees of swelling from 0.92 to 1.82. Drug release was controlled by both diffusion and swelling mechanisms, as supported by the Higuchi and Korsmeyer-Peppas models. The optimised formulation demonstrated high drug encapsulation efficiency, pH-responsive swelling, and strong adhesion to the colon, ensuring extended retention at the targeted site. Additionally, the incorporation of sericin enhanced the accuracy of Gaussian fitting for particle size distribution. Overall, the dual cross-linked sericin-pectin beads show potential as mucoadhesive carriers for delivering drugs specifically to the colon.

A Comprehensive Review of Challenges in Oral Drug Delivery Systems and Recent Advancements in Innovative Design Strategies

The oral route of drug administration is often preferred by patients and healthcare providers due to its convenience, ease of use, non-invasiveness, and patient acceptance. However, traditional oral dosage forms have several limitations, including low bioavailability, limited drug loading capacity, and stability and storage issues, particularly with solutions and suspensions. Over the years, researchers have dedicated considerable effort to developing novel oral drug delivery systems to overcome these limitations. This review discusses various challenges associated with oral drug delivery systems, including biological, pharmaceutical, and physicochemical barriers. It also explores common delivery approaches, such as gastroretentive drug delivery, small intestine drug delivery, and colon-targeting drug delivery systems. Additionally, numerous strategies aimed at improving oral drug delivery efficiency are reviewed, including solid dispersion, absorption enhancers, lipidbased formulations, nanoparticles, polymer-based nanocarriers, liposomal formulations, microencapsulation, and micellar formulations. Furthermore, innovative approaches like orally disintegrating tablets (ODT), orally disintegrating films (ODF), layered tablets, micro particulates, self-nano emulsifying formulations (SNEF), and controlled release dosage forms are explored for their potential in enhancing oral drug delivery efficiency and promoting patients' compliance. Overall, this review highlights significant progress in addressing challenges in the pharmaceutical industry and clinical settings, offering novel approaches for the development of effective oral drug delivery systems.

Novel drug delivery systems for hirudin-based product development and clinical applications

Hirudin, a natural biological polypeptide macromolecule secreted by the salivary glands of medicinal leech, is a specific thrombin inhibitor with multiple favourable bioactivities, including anti-coagulation, anti-fibrotic, and anti-tumour. Despite several anticoagulants have been widely applied in clinic, hirudin shows advantages in reducing the incidence of bleeding side effects by virtue of its high specificity in binding to thrombin. As a result, hirudin has been tested in clinical practice to prevent and treat several complex diseases. However, the application of this polypeptide macromolecule is compromised by its low bioavailability and bioactivity due to poor serum stability and susceptibility to protease degradation in vivo. To overcome these drawbacks, several studies have proposed novel drug delivery systems (NDDSs) to prevent the degradation and increase the targeting efficiency of hirudin. This systematic review summarises the clinical research on hirudin, including its classification and bioactivities, and highlights the opportunities and challenges in the clinical use of hirudin. The NDDSs designed to enhance the bioavailability and bioactivity of hirudin are discussed to explore its application in the treatment of related diseases. This review may considerably contribute to the advancement of delivery science and technology, particularly in the context of polypeptide-based therapeutics.

In-vivo and in-vitro assessment of curcumin loaded bile salt stabilized nanovesicles for oral delivery

BACKGROUND

Bile salts enriched nanovesicles (bilosomes) have been attention worthy in the past few years due to their distinctive effect on the enhancement of drug delivery through various physiological administration routes. Oral delivery of multifunctioning phytochemical curcumin has faced a lot of difficulties due to its scarce solubility and poor oral bioavailability.

OBJECTIVE

The current investigation aimed to develop curcumin loaded bilosomes for improvement of oral curcumin bioavailability with maximum efficiency and safety.

METHODS

The effect of formulation variables (type of span, SDC % to total lipid content Span/Cholesterol molar ratio) on physicochemical characterization and in vitro drug release in simulated intestinal fluid was investigated. Furthermore, in-vivo protective effect of bilosomes on hepatic and renal functions was also studied.

RESULTS

and conclusion. The results revealed that the best curcumin loaded bilosomal formulation showed spherical nanovesicular morphology with particle size 145.1 ± 19.42 nm with highly reasonable %EE (93%), Zeta potential (≥ -30mv), prominent controlled in-vitro release reaching 55.18 ± 1.10 after 96 h. The formulation also showed good storage stability with negligible differences in physical features and content. The IC50 values of bilosomal, niosomal, and free curcumin were 216.50, 211.44, and 121.63 mmol/ml, respectively revealing that the unencapsulated curcumin displayed high toxicity on Caco2 cell line (nearly 2 folds). Additionally, the prepared bilosomes showed significant in-vivo hepatic and renal protection in liver cirrhosis induced rats with conservation to all liver and renal markers and histopathological morphology. The study assumes the effectiveness and safety of oral delivery of curcumin loaded bile salts stabilized nanovesicles and its powerful commandment for further investigations.

Simulated Gastrointestinal Fluids Impact the Stability of Polymer-Functionalized Selenium Nanoparticles: Physicochemical Aspects

Background

Selenium (Se) is a vital micronutrient for maintaining homeostasis in the human body. Selenium nanoparticles (SeNPs) have demonstrated improved bioavailability compared to both inorganic and organic forms of Se. Therefore, supplementing with elemental Se in its nano-form is highly promising for biomedical applications related to Se deficiency.

Purpose

The primary objective of this study was to evaluate the impact of the main gastrointestinal proteins on the physicochemical properties and stability of polymer-coated SeNPs.

Methods

SeNPs functionalized with thiolated chitosan or hyaluronic acid were characterized based on their composition, morphology, size, and zeta potential. The stability of these particles was evaluated in simulated gastric and intestinal fluids. Additionally, the interaction propensity between major gastric proteins, such as pepsin and pancreatin, and functionalized SeNPs was investigated with FTIR, fluorescence quenching titrations, and in situ adsorption measurements.

Results

The composition of the media, including pH and ionic strength, the chemistry of polymers, and the presence of the proteins, influence the size and zeta potential of the SeNPs. The increase in NP size due to the formation of large agglomerates, along with the decrease in zeta potential magnitude, confirmed the formation of a protein corona. Both pepsin and pancreatin showed a strong affinity to the particle surface. Based on the values of the apparent equilibrium dissociation constant this affinity was more pronounced for positively charged thiolated chitosan coated SeNPs compared to those coated with negatively charged hyaluronic acid. The polymer coated SeNPs displayed antioxidative potential, which could be very beneficial for health conditions associated with Se-deficiency.

Conclusion

This study highlights the importance of exploring the characteristics of polymer-functionalized SeNPs under gastrointestinal conditions. Such investigations are important for developing nutritional supplements that can gradually release Se from SeNPs, thereby improving selenium absorption, bioavailability, and safety.

An efficient injection protocol for Drosophila larvae

Intravenous injection provides a direct, rapid, and efficient route for delivering drugs or other substances, particularly for compounds with poor intestinal absorption or molecules (e.g. proteins) that are prone to structural changes and degradation within the digestive system. While Drosophila larvae represent a well-established genetic model for studying developmental and physiological pathways, as well as human diseases, their use in analyzing the molecular effects of substance exposure remains limited. In this study, we present a highly efficient injection method for Drosophila first- and second-instar larvae. Despite causing a slight developmental delay, this method achieves a high survival rate and offers a quick, easily adjustable protocol. The process requires 3-5 h to inject 150-300 larvae, depending on the microcapillary needle, microinjection system, and the compound being administered. As proof of concept, we compared the effects of injecting ferritin protein into Fer1HCH00451 mutant first instar larvae with those of dietary ferritin administration. Our results show that ferritin injection rescues Fer1HCH mutants, a result that cannot be achieved through dietary delivery. This approach is particularly valuable for the delivery of complex compounds in cases where oral administration is impaired or limited by the digestive system.

Microneedles as an Emerging Platform for Transdermal Delivery of Phytochemicals

Phytochemicals, which are predominantly found in plants, hold substantial medicinal value. Despite their potential, challenges such as poor oral bioavailability and instability in the gastrointestinal tract have limited their therapeutic use. Traditional intra/transdermal drug delivery systems offer some advantages over oral administration but still suffer from issues such as limited penetration depth, slow drug release rates, and inconsistent drug absorption. In contrast, microneedles (MNs) represent a significant advancement in intra/transdermal drug delivery by providing precise control over phytochemical delivery and enhanced penetration capabilities. By circumventing skin barriers, MNs directly access dermal layers rich in blood vessels and lymphatics, thus facilitating efficient phytochemical delivery. This review extensively discusses the obstacles of traditional oral delivery and the benefits of intra/transdermal delivery routes with a particular focus on the transformative potential of MNs for phytochemical delivery. This review explores the complexities of delivering phytochemicals through intra/transdermal routes, the development and types of MNs as innovative delivery tools, and the optimal design and properties of MNs for effective phytochemical delivery. Additionally, this review examines the versatile applications of MN-mediated phytochemical delivery, including its role in administering phytophotosensitizers for photodynamic therapy, and concludes with insights into relevant patents and future perspectives.

pH-sensitive aminated chitosan/carboxymethyl cellulose/aminated graphene oxide coated composite microbeads for efficient encapsulation and sustained release of 5-fluorouracil

The application of smart pH-sensitive carriers has become an ideal choice for administering drugs with desired release profiles. Although pH-sensitive microbeads offer distinct benefits for delivering anticancer drugs orally, they encounter drawbacks, including low encapsulation efficiency, weak mechanical stability, biocompatibility concerns, and the risk of abrupt release. This study focuses on developing pH-sensitive coated composite microbeads for effective encapsulation and sustained release of 5-fluorouracil (5-FU). Aminated graphene oxide (AmGO) was integrated into carboxymethyl cellulose (CMC) microbeads, which were subsequently coated with an aminated chitosan (AmCs) derivative. Various analysis techniques, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analyzer (TGA), zeta potential (ZP), and mechanical testing, were utilized to characterize the microbeads. The AmCs@CMC@AmGO composite microbeads demonstrated a compact structure with enhanced mechanical properties, achieving a maximum Young's modulus value of 35.99 N/mm2 compared to 25.95 N/mm2 for pure CMC microbeads. Moreover, pH-sensitivity and water uptake studies (at pH 1.2 and pH 7.4) revealed significant tunability of the composite microbeads by altering the AmGO and AmCs ratios. The coated composite microbeads encapsulated approximately 86.4 % of 5-FU compared to 47 % for CMC microbeads. The burst release of 5-FU at pH 7.4 was significantly reduced, with sustained release reaching 51 % over 24 h. The predominant release mechanism was Fickian diffusion, which well-described by the Peppas-Sahlin kinetic model. The developed microbeads exposed improved biodegradability and non-toxicity toward normal colon cells, while exhibiting notable toxicity against cancerous cells, emphasizing its potential for anticancer drug delivery.

Cellular probing using phytoceuticals encapsulated advanced delivery systems in ameliorating lung diseases: Current trends and future prospects

Chronic respiratory diseases such as Chronic Obstructive Pulmonary Disease (COPD) and asthma have posed a significant healthcare and economic cost over a prolonged duration worldwide. At present, available treatments are limited to a range of preventive medicines, such as mono- or multiple-drug therapy, which necessitates daily use and are not considered as viable treatments to reverse the inflammatory processes of airway remodelling which is inclusive of the alteration of intra and extracellular matrix of the airway tract, death of epithelial cells, the increase in smooth muscle cell and the activation of fibroblasts. Hence, with the problem in mind a considerable body of study has been dedicated to comprehending the underlying factors that contribute to inflammation within the framework of these disorders. Hence, adequate literature that has unveiled the necessary cellular probing to reduce inflammation in the respiratory tract by improving the selectivity and precision of a novel treatment. However, through cellular probing cellular mechanisms such as the downregulation of various markers, interleukin 8, (IL-8), Interleukin 6 (IL-6), interleukin 1β (IL-1β) and tumor necrosis factor-α (TNF-α) have been uncovered. Hence, to target such cellular probes implementation of phytoceuticals encapsulated in an advanced drug delivery system has shown potential to be a solution with in vitro and in vivo studies highlighting their anti-inflammatory and antioxidant effects. However, the high costs associated with advanced drug delivery systems and the limited literature focused exclusively on nanoparticles pose significant challenges. Additionally, the biochemical characteristics of phytoceuticals due to poor solubility, limited bioavailability, and difficulties in mass production makes it difficult to implement this product as a treatment for COPD and asthma. This study aims to examine the integration of many critical features in the context of their application for the treatment of chronic inflammation in respiratory disorders.

Surface engineering of orthopedic implants for better clinical adoption

Musculoskeletal disorders are on the rise, and despite advances in alternative materials, treatment for orthopedic conditions still heavily relies on biometal-based implants and scaffolds due to their strength, durability, and biocompatibility in load-bearing applications. Bare metallic implants have been under scrutiny since their introduction, primarily due to their bioinert nature, which results in poor cell-material interaction. This challenge is further intensified by mechanical mismatches that accelerate failure, tribocorrosion-induced material degradation, and bacterial colonization, all contributing to long-term implant failure and posing a significant burden on patient populations. Recent efforts to improve orthopedic medical devices focus on surface engineering strategies that enhance the interaction between cells and materials, creating a biomimetic microenvironment and extending the service life of these implants. This review compiles various physical, chemical, and biological surface engineering approaches currently under research, providing insights into their potential and the challenges associated with their adoption from bench to bedside. Significant emphasis is placed on exploring the future of bioactive coatings, particularly the development of smart coatings like self-healing and drug-eluting coatings, the immunomodulatory effects of functional coatings and biomimetic surfaces to tackle secondary infections, representing the forefront of biomedical surface engineering. The article provides the reader with an overview of the engineering approaches to surface modification of metallic implants, covering both clinical and research perspectives and discussing limitations and future scope.

Evaluation of floatability characteristics of gastroretentive tablets using VIS imaging with artificial neural networks

Gastroretentive dosage forms are recommended for several active substances because it is often necessary for the drug to be released from the carrier system into the stomach over an extended period. Among gastroretentive dosage forms, floating tablets are a very popular pharmaceutical technology. In this study, it was investigated whether a rapid, nondestructive method can be used to characterize the floating properties of a tablet. To accomplish our objective, the same composition was compressed, and varied compression forces were applied to achieve the desired tablet. In addition to physical examinations, digital microscopic images of the tablets were captured and analyzed using image analysis techniques, allowing the investigation of the floatability of the dosage form. Image processing algorithms and artificial neural networks (ANNs) were utilized to classify the samples based on their strength and floatability. The input dataset consisted solely of the acquired images. It has been shown by our research that visible imaging coupled with pattern recognition neural networks is an efficient way to categorize these samples based on their floatability. Rapid and non-destructive digital imaging of tablet surfaces is facilitated by this method, offering insights into both crushing strength and floating properties.

Effect of food on oral pharmacokinetics of edaravone coamorphous dispersion containing bile salts as coformers - Part II

OBJECTIVES

Edaravone (EDR) is an effective neuroprotective agent in various neurological diseases; however, its use is restricted due to poor oral absorption. Bile salts are known for improving solubility and inhibiting drug crystallization in supersaturated conditions of the gastrointestinal tract (GIT). In our previous work, we prepared coamorphous dispersion (COAM) of EDR with sodium taurocholate (NaTC) using spray drying. The optimized EDR COAM exhibited superior in vitro performance compared to plain EDR. EDR is well absorbed in fasted-over-fed conditions.

METHODS

The present work, we conducted a pharmacokinetic study for EDR and EDR COAM in fasted and fed conditions to check effect of food on its oral absorption. The LC-MS/MS-based method was developed and validated to determine the amount of EDR in plasma.

RESULTS

The results suggested that EDR COAM did not show a significant difference in Cmax (P=0.3544) and AUC (P=0.1696) of fasted and fed states. On the other hand, plain EDR showed 2-fold and 3-fold reduced Cmax (P<0.0001) and AUC (P=0.0094) in the fed condition, respectively. The Cmax and AUC of EDR COAM were improved in fasted (AUC: 2.56-fold) and fed states (AUC: 5.74-fold) than plain EDR, suggesting better oral absorption of COAM than crystalline EDR without having the effect of food.

CONCLUSIONS

The unique structural attributes of NaTC had the potential to inhibit the recrystallization of EDR in GIT, while concurrently reducing the impact of food on the oral absorption of EDR.

Soybean β-Conglycinin and Cowpea β-Vignin Peptides Inhibit Breast and Prostate Cancer Cell Growth: An In Silico and In Vitro Approach

B-cell lymphoma 2 protein (Bcl-2) is an important regulator of cell apoptosis. Inhibitors that mirror the structural domain 3 (BH3) of Bcl-2 can activate apoptosis in cancer cells, making them a promising target for anticancer treatment. Hence, the present study aimed to investigate potential BH3-mimetic peptides from two vicilin-derived legume proteins from soybean and cowpea bean. The proteins were isolated and sequentially hydrolyzed with pepsin/pancreatin. Peptides < 3 kDa from vicilin-derived proteins from soybean and cowpea beans experimentally inhibited the growth of cultivated breast and prostate cancer cells. In silico analysis allowed the identification of six potential candidates, all predicted to be able to interact with the BH3 domain. The VIPAAY peptide from the soybean β-conglycinin β subunit showed the highest potential to interact with Bcl-2, comparable to Venetoclax, a well-known anticancer drug. Further experiments are needed to confirm this study's findings.

Preparation of ternary hybridized chitosan microspheres with photothermal effect for pH-sensitive long-lasting controlled release system and its release mechanism

To enhance the effective utilization of drugs and diminish the number of medications for patients, it is vital to investigate controlled long-acting drug release systems and their release mechanisms. In this study, chitosan microspheres were synthesized by cross-linking pH-sensitive Schiff bases, and Zif-8, a pH-sensitive component, was encapsulated within them. Furthermore, MXene was incorporated as a third component to augment the strength and photothermal synergistic characteristics of the microspheres. By adjusting the ratio of each component, the optimal ternary heterogeneous functional pH-controllable long-lasting drug release system was obtained. The optimal coating and the most effective adsorption-release effect were achieved. The release mechanism was examined under varying pH and temperature conditions. The release process was found to be divided into three stages. The initial phase was predominantly governed by the Fick diffusion mechanism, whereas the subsequent phases were primarily regulated by the pH-induced co-decomposition of CS and Zif-8, and the individual decomposition of CS, respectively. The drug was observed to be released in a linear manner during the latter two stages of the experiment. This was evidenced by the persistent release of ciprofloxacin hydrochloride in response to pH changes, and further supported by the results of tests on its antimicrobial properties. The drug release persisted for over three days at pH 5.4 and could be utilized repeatedly, exhibiting promising applications in drug delivery. Moreover, the drug's photothermal properties offer the possibility of developing synergistic therapeutic programs.

Lipid-Based Nanoformulations for Drug Delivery: An Ongoing Perspective

Oils and lipids help make water-insoluble drugs soluble by dispersing them in an aqueous medium with the help of a surfactant and enabling their absorption across the gut barrier. The emergence of microemulsions (thermodynamically stable), nanoemulsions (kinetically stable), and self-emulsifying drug delivery systems added unique characteristics that make them suitable for prolonged storage and controlled release. In the 1990s, solid-phase lipids were introduced to reduce drug leakage from nanoparticles and prolong drug release. Manipulating the structure of emulsions and solid lipid nanoparticles has enabled multifunctional nanoparticles and the loading of therapeutic macromolecules such as proteins, nucleic acid, vaccines, etc. Phospholipids and surfactants with a well-defined polar head and carbon chain have been used to prepare bilayer vesicles known as liposomes and niosomes, respectively. The increasing knowledge of targeting ligands and external factors to gain control over pharmacokinetics and the ever-increasing number of synthetic lipids are expected to make lipid nanoparticles and vesicular systems a preferred choice for the encapsulation and targeted delivery of therapeutic agents. This review discusses different lipids and oil-based nanoparticulate systems for the delivery of water-insoluble drugs. The salient features of each system are highlighted, and special emphasis is given to studies that compare them.

Nanotechnology-based approaches for targeted drug delivery for the treatment of respiratory tract infections

Background

Nanotechnology has emerged as a promising field for the diagnosis, monitoring, and treatment of respiratory tract infections (RTIs). By leveraging the unique properties of nanoscale delivery systems, nanotechnology can significantly enhance the selectivity and efficacy of antimicrobials, thereby reducing off-target effects.

Objective

This review explores the development and application of targeted nanosystems in combating viral, bacterial, and fungal RTIs. Nanotechnology-based systems, including biological and non-biological nanoparticles, offer innovative solutions for overcoming antimicrobial resistance, improving drug bioavailability, and minimizing systemic side effects. RTIs are a leading cause of morbidity and mortality globally, particularly affecting vulnerable populations such as children, the elderly, and immunocompromised individuals. Traditional drug delivery methods face numerous challenges, such as rapid clearance, poor tissue penetration, and drug degradation. Nanoparticle-based delivery systems address these issues by enhancing tissue penetration, providing sustained drug release, and enabling targeted delivery to infection sites. These systems include liposomal delivery, polymeric nanoparticles, dendrimers, and metal-based nanoparticles, each offering unique advantages in treating RTIs. Nanotechnology also plays a crucial role in vaccine development by offering new strategies to enhance immune responses and improve antigen delivery. Furthermore, the review discusses the clinical translation and regulatory considerations for nanotechnology-based drug delivery, emphasizing the need for rigorous testing and quality control to ensure safety and efficacy.

Conclusion

Nanotechnology offers promising advancements in the treatment, and prevention of RTIs by enhancing drug delivery and efficacy. By addressing challenges such as antimicrobial resistance and poor tissue penetration, nanotechnology-based systems have the potential to significantly improve patient outcomes.

Recent Advances in the Drugs and Glucose-Responsive Drug Delivery Systems for the Treatment of Diabetes: A Systematic Review

Diabetes is a common chronic metabolic disease. Different types of drugs play important roles in controlling diabetes and its complications, but there are some limitations. The glucose-responsive drug delivery system is a novel technology with potential in diabetes treatment. It could automatically release drugs in response to changes in glucose levels in the body to maintain blood glucose within a normal range. The emergence of a glucose-sensitive drug delivery system provides a more intelligent and precise way to treat diabetes. The review is carried out according to the Preferred Reporting Items for Systematic Reviews (PRISMA 2020) guidelines This review focuses on the recent advances in the drugs and different systems of glucose-sensitive drug delivery, including glucose oxidase, phenylboronic acid, Concanavalin A, and other glucose-reactive systems. Furthermore, the glucose-responsive drug delivery system combined with the application applied in hydrogels, microneedles, and nanoparticles is also explored and summarized. The new platforms to sustain the release of anti-diabetic drugs could be desirable for patients. It could lead to increased adherence and glycemic outcomes for the detection and treatment of diabetes. Furthermore, given the limitations of glucose-responsive drug delivery systems, solutions and perspectives are proposed to help the understanding and application of these systems. This review will be helpful for drug discovery and treatment of diabetes from a new perspective.

Advancements in Drug Delivery Systems for the Treatment of Sarcopenia: An Updated Overview

Since sarcopenia is a progressive condition that leads to decreased muscle mass and function, especially in elderly people, it is a public health problem that requires attention from researchers. This review aims to highlight drug delivery systems that have a high and efficient therapeutic potential for sarcopenia. Current as well as future research needs to consider the barriers encountered in the realization of delivery systems, such as the route of administration, the interaction of the systems with the aggressive environment of the human body, the efficient delivery and loading of the systems with therapeutic agents, and the targeted delivery of therapeutic agents into the muscle tissue without creating undesirable adverse effects. Thus, this paper sets the framework of existing drug delivery possibilities for the treatment of sarcopenia, serving as an inception point for future interdisciplinary studies.

Smart Bioorthogonal Nanozymes: From Rational Design to Appropriate Bioapplications

Bioorthogonal chemistry has provided an elaborate arsenal to manipulate native biological processes in living systems. As the great advancement of nanotechnology in recent years, bioorthogonal nanozymes are innovated to tackle the challenges that emerged in practical biomedical applications. Bioorthogonal nanozymes are uniquely positioned owing to their advantages of high customizability and tunability, as well as good adaptability to biological systems, which bring exciting opportunities for biomedical applications. More intriguingly, the great advancement in nanotechnology offers an exciting opportunity for innovating bioorthogonal catalytic materials. In this comprehensive review, the significant progresses of bioorthogonal nanozymes are discussed with both spatiotemporal controllability and high performance in living systems, and highlight their design principles and recent rapid applications. The remaining challenges and future perspectives are then outlined along this thriving field. It is expected that this review will inspire and promote the design of novel bioorthogonal nanozymes, and facilitate their clinical translation.

"Enhancing Oral Drug Absorption: Overcoming Physiological and Pharmaceutical Barriers for Improved Bioavailability"

The oral route stands out as the most commonly used method for drug administration, prized for its non-invasive nature, patient compliance, and easy administration. Several elements influence the absorption of oral medications, including their solubility, permeability across mucosal membranes, and stability within the gastrointestinal (GI) environment. Research has delved into comprehending physicochemical, biochemical, metabolic, and biological obstacles that impact the bioavailability of a drug. To improve oral drug absorption, several pharmaceutical technologies and delivery methods have been studied, including cyclodextrins, micelles, nanocarriers, and lipid-based carriers. This review examines both traditional and innovative drug delivery methods, as well as the physiological and pharmacological barriers influencing medication bioavailability when taken orally. Additionally, it describes the challenges and advancements in developing formulations suitable for oral use.

Development of quercetin-loaded electrospun nanofibers through shellac coating on gelatin: Characterization, colon-targeted delivery, and anticancer activity

Quercetin possesses multiple biological activities. To achieve efficient colon-specific release of quercetin, new composite nanofibers were developed by coating pH-responsive shellac on hydrophilic gelatin through coaxial electrospinning. These composite nanofibers contained bead-like structures. The encapsulation efficiency (87.6-98.5 %) and loading capacity (1.4-4.1 %) varied with increasing the initial quercetin addition amount (2.5-7.5 %). FTIR, XRD, and TGA results showed that the quercetin was successfully encapsulated in composite nanofibers in an amorphous state, with interactions occurring among quercetin, gelatin, and shellac. Composite nanofibers had pH-responsive surface wettability due to the shellac coating. In vitro digestion experiments showed that these composite nanofibers were highly stable in the upper gastrointestinal tract, with quercetin release ranging from 4.75 % to 12.54 %. In vivo organ distribution and pharmacokinetic studies demonstrated that quercetin could be sustainably released in the colon after oral administration of composite nanofibers. Besides, the enhanced anticancer activity of composite nanofibers was confirmed against HCT-116 cells by analyzing their effect on cell viability, cell cycle, and apoptosis. Overall, these novel composite nanofibers could deliver efficiently quercetin to the colon and achieve its sustained release, thus potential to regulate colon health. This system is also helpful in delivering other bioactives to the colon and exerting their functional effects.

Oral food-derived whey protein isolate-Tremella fuciformis polysaccharides pickering emulsions with adhesive ability to delivery magnolol for targeted treatment of ulcerative colitis

Magnolol (Mag) is a promising natural compound with therapeutic potential for ulcerative colitis (UC). Here we designed and fabricated an oral food-grade whey protein isolate-Tremella fuciformis polysaccharides (WPI-TFPS) stabilized pickering emulsions to encapsulate Mag (Mag-WPI-TFPS) for targeted treatment of UC. With the assistance of the WPI-TFPS, pickering emulsions were well encapsulated and formed stable microparticles with a particle size of approximately 9.49 ± 0.047 μm, a 93.63 ± 0.21 % encapsulation efficiency and a loading efficiency of 21.53 ± 0.01 %. In vitro, the formulation exhibited sustained-release properties in simulated colon fluid with a cumulative release rate of 60.78 % at 48 h. In vivo, the Mag-WPI-TFPS specifically accumulated in the colon tissue for 24 h with stronger fluorescence intensity, which demonstrated that TFPS and WPI had a good adherence ability to inflamed mucosa by electrostatic attraction and ligand-receptor interactions. As expected, compared with Free-Mag, the oral administration of Mag-WPI-TFPS remarkably alleviated the symptoms of UC and protected the colon tissue in DSS-induced UC mice. More importantly, WPI-TFPS enhanced gut microbiota balance by increasing the diversity and relative abundances of Lactobacillaceae and Firmicutes. Overall, this study presents a convenient, eco-friendly, food-derived oral formulation with potential as a dietary supplement for targeted UC treatment.

Self-nanomicellizing solid dispersion: A promising platform for oral drug delivery

Amorphous solid dispersion (ASD) has been widely used to enhance the oral bioavailability of water-insoluble drugs for oral delivery because of its advantages of enhancing solubility and dissolution rate. However, the problems related to drug recrystallization after drug dissolution in media or body fluid have constrained its application. Recently, a self-nanomicellizing solid dispersion (SNMSD) has been developed by incorporating self-micellizing polymers as carriers to settle the problems, markedly improving the ability of supersaturation maintenance and enhancing the oral bioavailability of drug. Spontaneous formation and stability of the self-nanomicelle (SNM) have been proved to be the key to supersaturation maintenance of SNMSD system. This offers a novel research direction for maintaining supersaturation and enhancing the bioavailability of ASDs. To delve into the advantages of SNMSDs, we provide a concise review introducing the formation mechanism, characterization methods and stability of SNMs, emphasizing the advantages of SNMSDs for oral drug delivery facilitated by SNM formation, and discussing relevant research prospects.

Unlocking the Potential of Camel Milk-Derived Exosomes as Novel Delivery Systems: Enhanced Bioavailability of ARV-825 PROTAC for Cancer Therapy

This study investigates the use of camel milk-derived exosomes (CMEs) as carriers for ARV-825, an anticancer agent targeting bromodomain-containing protein 4 (BRD4), in oral chemotherapy. CMEs were isolated and characterized, and ARV-825-loaded CME formulations were prepared and evaluated through various in vitro and in vivo tests. The ARV-825-CME formulation exhibited an entrapment efficiency of 42.75 ± 5.05%, a particle size of 136.8 ± 1.94 nm, and a zeta potential of -32.75 ± 0.70 mV, ensuring stability and sustained drug release. In vitro studies showed a 5.4-fold enhancement in drug release kinetics compared to the free ARV-825 solution. Permeability studies indicated a 3.2-fold increase in apparent permeability, suggesting improved cellular uptake. Cytotoxicity assays demonstrated potent anticancer activity, with IC50 values decreasing by 1.5 to 2-fold in cancer cell lines SF8628 DIPG and H1975R (resistant to Osimertinib). In vivo pharmacokinetic studies in Sprague-Dawley rats revealed superior systemic absorption and bioavailability of ARV-825 from CMEs, with a 2.55-fold increase in plasma concentration and a 5.56-fold increase in AUC. Distribution studies confirmed absorption through the ileum. This research highlights the potential of CMEs as a promising delivery platform for ARV-825, enhancing its therapeutic efficacy and offering a novel approach to cancer treatment.

Precise antibiotic delivery to the lung infection microenvironment boosts the treatment of pneumonia with decreased gut dysbiosis

Bacterial pneumonia is a common disease with significant health risks. However, the overuse antibiotics in clinics face challenges such as inadequate targeting and limited drug utilization, leading to drug resistance and gut dysbiosis. Herein, a dual-responsive lung inflammatory tissue targeted nanoparticle (LITTN), designed for targeting lung tissue and bacteria, is screened from a series of prepared nanoparticles consisting of permanent cationic lipids, acid-responsive lipids, and reactive oxygen species-responsive and phenylboronic acid-modified lipids with different surface properties. Such nanoparticle is further verified to enhance the adsorption of vitronectin in serum. Additionally, the optimized nanoparticle exhibits more positive charge and coordination of boric acid with cis-diol in the infected microenvironment, facilitating electrostatic interactions with bacteria and biofilm penetration. Importantly, the antibacterial efficiency of dual-responsive rifampicin-loaded LITTN (Rif@LITTN) against methicillin-resistant staphylococcus aureus is 10 times higher than that of free rifampicin. In a mouse model of bacterial pneumonia, the intravenous administration of Rif@LITTN could precisely target the lungs, localize in the lung infection microenvironment, and trigger the responsive release of rifampicin, thereby effectively alleviating lung inflammation and reducing damage. Notably, the targeted delivery of rifampicin helps protect against antibiotic-induced changes in the gut microbiota. This study establishes a new strategy for precise delivery to the lung-infected microenvironment, promoting treatment efficacy while minimizing the impact on gut microbiota. STATEMENT OF SIGNIFICANCE: Intravenous antibiotics play a critical role in clinical care, particularly for severe bacterial pneumonia. However, the inability of antibiotics to reach target tissues causes serious side effects, including liver and kidney damage and intestinal dysbiosis. Therefore, achieving precise delivery of antibiotics is of great significance. In this study, we developed a novel lung inflammatory tissue-targeted nanoparticle that could target lung tissue after intravenous administration and then target the inflammatory microenvironment to trigger dual-responsive antibiotics release to synergistically treat pneumonia while maintaining the balance of gut microbiota and reducing the adverse effects of antibiotics. This study provides new ideas for targeted drug delivery and reference for clinical treatment of pneumonia.

Biomedical applications of stimuli-responsive nanomaterials

Nanomaterials have aroused great interests in drug delivery due to their nanoscale structure, facile modifiability, and multifunctional physicochemical properties. Currently, stimuli-responsive nanomaterials that can respond to endogenous or exogenous stimulus display strong potentials in biomedical applications. In comparison with conventional nanomaterials, stimuli-responsive nanomaterials can improve therapeutic efficiency and reduce the toxicity of drugs toward normal tissues through specific targeting and on-demand drug release at pathological sites. In this review, we summarize the responsive mechanism of a variety of stimulus, including pH, redox, and enzymes within pathological microenvironment, as well as exogenous stimulus such as thermal effect, magnetic field, light, and ultrasound. After that, biomedical applications (e.g., drug delivery, imaging, and theranostics) of stimuli-responsive nanomaterials in a diverse array of common diseases, including cardiovascular diseases, cancer, neurological disorders, inflammation, and bacterial infection, are presented and discussed. Finally, the remaining challenges and outlooks of future research directions for the biomedical applications of stimuli-responsive nanomaterials are also discussed. We hope that this review can provide valuable guidance for developing stimuli-responsive nanomaterials and accelerate their biomedical applications in diseases diagnosis and treatment.

Research progress of sorafenib drug delivery system in the treatment of hepatocellular carcinoma: An update

Hepatocellular carcinoma (HCC) is one of the most prevalent malignant tumors in the contemporary era, representing a significant global health concern. Early HCC patients have mild symptoms or are asymptomatic, which promotes the onset and progression of the disease. Moreover, advanced HCC is insensitive to chemotherapy, making traditional clinical treatment unable to block cancer development. Sorafenib (SFB) is a first-line targeted drug for advanced HCC patients with anti-angiogenesis and anti-tumor cell proliferation effects. However, the efficacy of SFB is constrained by its off-target distribution, rapid metabolism, and multi-drug resistance. In recent years, nanoparticles based on a variety of materials have been demonstrated to enhance the targeting and therapeutic efficacy of SFB against HCC. Concurrently, the advent of joint drug delivery systems has furnished crucial empirical evidence for reversing SFB resistance. This review will summarize the application of nanotechnology in the field of HCC treatment over the past five years. It will focus on the research progress of SFB delivery systems combined with multiple therapeutic modalities in HCC treatment.