Mucosal Applications of Poloxamer 407-Based Hydrogels: An Overview

Smart hydrogel: A new platform for cancer therapy

Cancer is a significant contributor to mortality worldwide, posing a significant threat to human life and health. The unique bioactivity, ability to precisely control drug release, and minimally invasive properties of hydrogels are indispensable attributes that facilitate optimal performance in cancer therapy. However, conventional hydrogels lack the ability to dynamically respond to changes in the surrounding environment, withstand drastic changes in the microenvironment, and trigger drug release on demand. Therefore, this review focuses on smart-responsive hydrogels that are capable of adapting and responding to external stimuli. We comprehensively summarize the raw materials, preparation, and cross-linking mechanisms of smart hydrogels derived from natural and synthetic materials, elucidate the response principles of various smart-responsive hydrogels according to different stimulation sources. Further, we systematically illustrate the important role played by hydrogels in modern cancer therapies within the context of therapeutic principles. Meanwhile, the smart hydrogel that uses machine learning to design precise drug delivery has shown great prospects in cancer therapy. Finally, we present the outlook on future developments and make suggestions for future related work. It is anticipated that this review will promote the practical application of smart hydrogels in cancer therapy and contribute to the advancement of medical treatment.

Development of in vitro and in vivo evaluation of mucoadhesive in-situ gel for intranasal delivery of vinpocetine

ABSTRACT Alzheimer's disease (AD), which is marked by gradual neuronal decline and subsequent loss of cognitive functions and memory, poses significant treatment challenges. The present study involved the development, in vitro, and in vivo evaluation of a novel intranasal mucoadhesive in-situ gel of vinpocetine (VIN) with the aim to target the brain. An innovative gel formulation composed of poloxamer 407, HPMC E15 LV, and citric acid as a solubilizer was developed by 23 Factorial Design. The developed optimal formulation exhibited favorable rheological properties as it displayed ideal gelation time (31.6 ± 1.52 sec), optimum gelling temperature (32 ± 1.0 °C), enhanced mucoadhesive strength (6622 ± 2.64 dynes/cm2), prolonged adhesion (7.22 ± 0.57 hrs) compared with the baseline formulation (F18), and improved drug release in 12 hrs (39.59 ± 1.6%). In vivo, pharmacokinetics revealed a significant increase in Cmax (∼2-fold) and AUC0-t (∼2-fold) in the brain with the in-situ intranasal gel compared to the oral route. In the rat model of AD, in-situ intranasal gel demonstrated significantly greater efficacy (p < 0.001) than oral administration in alleviating AD symptoms as evidenced by behavioral and histological studies. Thus, VIN in-situ gel can be safe and noninvasive for nose-to-brain drug delivery.

Enhanced therapeutic approach for vaginal candidiasis: chitosan nanoparticulate thermoreversible in situ gels for sustained clotrimazole delivery

This study aimed to develop and evaluate clotrimazole (CLZ)-loaded chitosan (CS) nanoparticles in a thermoreversible in situ gel for treating vaginal candidiasis (VC). Chitosan nanoparticles (CS-NPs) were prepared using ionotropic gelation with optimization through the design of experiments (DoE), considering factors such as chitosan pH, sodium tripolyphosphate (TPP) pH, the ratio of chitosan to TPP, and drug. Under optimal conditions (pH of CS, TPP, CS: TPP, and drug at 2, 2, 4:1, and 10 mg), nanoparticles exhibited desirable properties: particle size of 101.7 nm, polydispersity index (PDI) of 0.108, zeta potential of 35.4, and encapsulation efficiency of 98.36%. Thermoreversible in situ gels incorporating poloxamer (PXM) 407 and 188 were produced via the cold method and evaluated for mechanical and physicodynamic properties. It was found that nanoparticulate thermoreversible gel (NTG) prepared with 24% PXM 407, 4% PXM 188, 0.5% HPMC E-50, or 0.5% chitosan is suitable for vaginal administration, since it fulfills the in situ gel characteristics such as pH (4.7), gelation temperature and time (36 ℃ ± 0.2 and 4 ± 0.2 min), and viscosity (2690 cP (centipoise) at 25 ℃ and 15,600 cP at 37 ℃). In vitro release studies for the developed formulation showed 98% drug release over 72 h, with an extended residence time compared to the marketed formulation. In vitro antifungal and cytocompatibility studies revealed that the developed NTG was effective against VC and free from cytotoxicity.

Enhancing the stability and catalytic efficiency of alkyl halide dehalogenase through poloxamer temperature-sensitive gel

Dha A, a biocatalyst with pronounced efficacy in the degradation of mustard gas, is constrained by its inherent instability, which impedes its broader application. In this study, we encapsulated Dha A within a poloxamer-based thermosensitive hydrogel, a widely utilized protein carrier, to assess its physicochemical characteristics, catalytic performance, and stability enhancement. The Dha A-loaded thermosensitive gel (Dha A@TSG) exhibited interactions between Dha A and poloxamer molecules via hydrogen bonding, with an optimal gelation temperature of 25°C. This encapsulation strategy significantly enhanced the solubility and catalytic efficiency of the mustard gas mimic, bis(2-chloroethyl) ether, surpassing the performance of the free Dha A solution. At 32°C, the poloxamer molecules within Dha A@TSG formed a tightly packed stereostucture, which substantially improved the storage and thermal stability of Dha A. Collectively, our findings offer valuable technical insights into the stabilization and catalytic efficiency enhancement of Dha A through the employment of poloxamer thermosensitive gels.

Amorphous Roxithromycin Loaded in-situ Gel for the Treatment of Staphylococcus aureus Induced Upper Respiratory Tract Infection

Objective

Upper respiratory tract infections are among the most prevalent respiratory diseases, imposing both financial and physical burdens on affected individuals. Roxithromycin (ROX), a primary drug for treating bacterial-induced respiratory tract infections, is typically administered orally due to its hydrophobic nature. However, the non-specific distribution resulting from oral administration reduces bioavailability and can cause side effects such as diarrhea.

Methods

In this study, we prepared a thermo-sensitive in-situ gel using a facile and highly reproducible method by simply mixing two types of poloxamers with ROX.

Results

The ROX can be well dissolved in the poloxamer matrix in amorphous state to give solution. Upon intranasal administration, the ROX solution undergoes a phase transition to form in-situ gel under body temperature. This gel remains in the nasal cavity for an extended period, releasing the drug directly to the site of infection and minimizing non-specific distribution. Pharmacokinetic experiments revealed that, compared to oral administration, the bioavailability of local nasal administration increased by 1.5 times, and the drug concentration in the local nasal cavity increased by 8 times. In contrast, concentrations in the liver and small intestine did not significantly differ from those following oral administration. In vivo antibacterial experiments also showed that the ROX in-situ gel has superior antibacterial efficacy and excellent biocompatibility.

Conclusion

These results suggest that the thermo-sensitive ROX in-situ gel is a promising formulation for treating bacterial upper respiratory tract infections.

Alpha-Ketoglutarate Alleviates Systemic Lupus Erythematosus-Associated Periodontitis in a Novel Murine Model

AIM

To establish a reproducible experimental animal model for systemic lupus erythematosus (SLE)-associated periodontitis (PD), investigate the effects of SLE on PD and assess the therapeutic potential of alpha-ketoglutarate (αKG) for SLE-PD treatment.

MATERIALS AND METHODS

An SLE-PD murine model was established via ligature-induced PD in MRL-lpr strain, with MRL/MpJ strain as a non-SLE control. The periodontal state was assessed using micro-CT, real-time PCR, histology, immunofluorescence and flow cytometry assays. αKG levels were analysed, and a thermoresponsive gel was designed as a periodontal dimethyl (DM)-αKG delivery system. αKG levels were analysed in gingival crevicular fluid (GCF) of PD patients with or without SLE.

RESULTS

SLE significantly increased the periodontal inflammation and bone resorption in the SLE-PD model. αKG levels in GCF were lower in PD patients with SLE than in PD patients without SLE. Decreased αKG levels in the gingiva and macrophage M1/M2 imbalance were observed in SLE-PD mice. However, DM-αKG thermoresponsive gel effectively alleviated the periodontal inflammation, bone resorption and macrophage M1/M2 imbalance in SLE-PD mice.

CONCLUSIONS

Our study established, for the first time, a novel SLE-PD murine model and revealed that SLE increases the severity of PD in vivo. Our findings highlight the therapeutic potential of αKG for SLE-associated PD.

Pickering Emulsion-Based Gels with Halloysite as a Stabilizer: Formulation, Mechanical Properties and In Vitro Drug Release Studies

Lidocaine is an analgesic agent frequently incorporated in topical formulations intended for application in minor surgical procedures or relieving neuropathic pain associated with numerous conditions, including post-herpetic neuralgia or diabetic peripheral neuropathy. In this study, Pickering o/w emulsions with halloysite nanotubes as a stabilizing agent and lidocaine incorporated in the internal phase were formulated with the use of the Quality by Design (QbD) approach. The selected emulsions were transformed into semisolid gels with poloxamer 407 as a thickening agent, and investigated for rheological and textural properties, indicating the mechanical features of the obtained gels. Moreover, the obtained formulations were tested for lidocaine release with the use of vertical Franz diffusion cells in order to assess the relationship between the applied composition and potential clinical applicability of the analyzed gels. The obtained results indicate that the emulsion droplet diameter is affected mostly by the oil and halloysite contents. The yield stress points, hardness and cohesiveness values of the obtained gels increased with the oil content. The drug release rate seems to be affected mostly by the concentration of the active ingredient in the oil phase.

Evaluation of a Novel Cisplatin Poloxamer Gel Formulation in the Treatment of Incompletely Excised Soft-Tissue Sarcomas: 42 Dogs

Soft-tissue sarcomas are a heterogenous group of mesenchymal tumours that occur in dogs. Complete surgical excision is the ideal treatment for this tumour, but often, the location of the tumour makes this challenging, and the morbidity and cost of such a procedure may be prohibitive. This study describes the use of intralesional cisplatin in a novel poloxamer gel formulation, injected into the tumour bed as an adjuvant treatment to try and lower rates of local recurrence following incomplete and marginal excision. This formulation of cisplatin transiently solidifies at body temperature and exposes the tumour bed to high concentrations of this cytotoxic drug. An overall recurrence rate of 36% (15/42) was recorded in this cohort, with recurrence more likely to occur in tumours that had previously recurred and in larger (≥50 mm) tumours. Whilst this drug formulation is easy to administer and is well tolerated, subsequent use should be weighed against other adjuvant options. Other clinical utilisations of poloxamers in veterinary oncology should be explored.

From Waste to Value: Solubility and Dissolution Enhancement of Bioactive Extracts from Olive Leaves Using Poloxamers

The European Union, producing over 2.5 billion tons of waste annually, has prompted the European Parliament to implement legal measures and encourage the shift towards a circular economy. Millions of tons of biowaste from olive plant leaves are generated annually, resulting in environmental and economic challenges. To address this, the biowaste of olive leaves was valorized, resulting in the extraction of valuable components, triterpenes and polyphenols, which hold potential pharmaceutical, food, or cosmetic applications. Our research involved the formulation of a triterpene extract (TTP70, 70% triterpenes) as a solid dispersion using Poloxamer-188 (P188) and Poloxamer-407 (P407). The solid dispersions were prepared using a kneading method and various extract-to-polymer weight ratios, including 1:1, 1:2, and 1:5. The influence of hydrophilic carriers on the solubility, dissolution profile, and in vitro passive permeability of TTP70 was evaluated. Both carriers and all considered weight ratios significantly improved the solubility of hydrophobic extract and the dissolution of triterpenes. PAMPA experiments demonstrated the efficacy of the formulation in improving the passive permeation of triterpenes. Subsequently, the solid dispersions were physically mixed with a polyphenol-enriched extract (OPA40, 49% of polyphenols) also obtained from olive leaves, and they were used to fill hard gelatin capsules and produce an oral dosage form. The composite formulations improved the dissolution of both classes of constituents.

Study on an Injectable Chitosan-Lignin/Poloxamer Hydrogel Loaded with Platelet-Rich Plasma for Intrauterine Adhesion Treatment

It is a great challenge to obtain an ideal hydrogel for the clinical treatment of intrauterine adhesion (IUA) disease. Here, a novel injectable chitosan-lignin/poloxamer hydrogel loaded with platelet-rich plasma (CL-PF127@PRP) was prepared by self-assembly at room temperature. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), rheological analysis, and injectable writing were used to characterize the structure of the hydrogel. The results confirmed that the amino group of chitosan and the sulfonic group of sodium lignosulfonate were ionic-crosslinked by electrostatic attraction, which stabilized the three-dimensional structure of the PF127 hydrogel loaded with PRP, and PRP made the porous structure gradually become tight. Moreover, the CL-PF127@PRP hydrogel displayed good injectability and a solid state. The soaking experiment showed that the CL-PF127@PRP hydrogel had suitable degradation at pH = 7 and a good PRP release rate (PRP release 70% at 96 h). Cell experiments in vitro demonstrated that the CL-PF127@PRP hydrogel possessed good biocompatibility, an anti-inflammatory function, and pro-angiogenic activity. Furthermore, an animal experiment of skin wound and IUA confirmed that the skin wound closure rate of the CL-PF127@PRP hydrogel was over 50% on the seventh day. PRP improved the thickness of the endometrium and uterus receptivity, suggesting that the CL-PF127@PRP hydrogel offers great promise for the clinical treatment of IUA.

Development and Characterization of Niaprazine-Loaded Xanthan Gum-Based Gel for Oral Administration

Niaprazine is a sedative-hypnotic drug initially developed as an antihistamine and used for its notable sedative effects, particularly in children. Following its withdrawal from the market by the producer, the drug has been administered as magistral formulations available in syrup form, but there are several important disadvantages to this, including instability, taste issues, lack of controlled release, and the potential for unreliable dosing due to incomplete swallowing. There is also an increased risk of dental caries, as well as the fact that these formulations are not suitable for children who suffer from diabetes. The purpose of the current investigation is to prepare and characterize xanthan gum-based gels for the oral administration of niaprazine. Niaprazine gels appear as transparent-whiteish, non-sticky substances, with the drug uniformly dispersed throughout the systems. They are also stable over time. Dynamic rheology revealed their advantageous shear-thinning properties, which enable the formulation to be flexibly dosed orally through administration via syringe. During experimentation, the evaluation of the mucoadhesion features and the in vitro drug release profile were also performed. The results demonstrate that the formulation may represent an alternative to niaprazine syrup, allowing easy preparation, administration, and increased compliance in various categories of patients, including pediatric.

Smart biomaterial gels for periodontal therapy: A novel approach

Periodontitis, a chronic inflammatory condition of the oral cavity, is characterized by the progressive destruction of the supporting structures of the teeth. The pathogenic effects of periodontopathogens extend beyond the local periodontal environment, contributing to systemic health complications, thereby underscoring the need for effective therapeutic strategies. Current standard treatments, which involve mechanical debridement coupled with systemic anti-inflammatory and antibiotic therapies, are often associated with limited efficacy, adverse effects, and the emergence of antibiotic resistance. Recent advancements in localized drug delivery systems present an innovative alternative, offering site-specific targeting with sustained therapeutic action. Smart drug delivery platforms, designed to respond to the unique microenvironment of periodontal pockets, undergo physicochemical transformations such as gelation or controlled drug release, enhancing treatment efficacy. This review comprehensively explores the etiological and prognostic factors of periodontitis, critical diagnostic biomarkers, and an in-depth analysis of stimuli-responsive biomacromolecule-based gels. These systems are evaluated for their structural properties, biological compatibility, and therapeutic potential while addressing their limitations and barriers to clinical translation. By integrating insights into the interplay between material properties and biological performance, this review highlights the future role of these advanced delivery systems in overcoming challenges in periodontal healthcare. Such approaches aim to bridge the gap between bench-side innovation and bedside application, offering the transformative potential to enhance therapeutic outcomes and improve patient quality of life in managing periodontal diseases.

Development of lacosamide-loaded in-situ gels through experimental design for evaluation of ocular irritation in vitro and in vivo

Lacosamide (LCM) selectively increases the slow inactivation of voltage-gated sodium channels (VGSCs) and is a N-methyl d-aspartate acid (NMDA) receptor glycine site antagonist. Therefore, it can be used in dryness-related hyperexcitability of corneal cold receptor nerve terminals. Ocular in-situ gels remain in liquid form until they reach the target site, where they undergo a sol-gel transformation in response to specific stimuli. They can show mucoadhesive properties related to the polymer used and increase the residence time of the drug in the mucosa. In the presented study, ocular in-situ gel formulation of LCM, which has potential for use in ocular diseases and consists of hyaluronic acid and poloxamer 407 as polymers, was developed using cold method. The effect of formulation components on target product properties (pH, gelation temperature and viscosity) was evaluated by design of experiments (DoE) design. The optimized LCM-loaded in-situ gel had a pH value of 6.90 ± 0.01, showed pseudo-plastic flow with a viscosity of 562 ± 58 cP at 25 °C, gelled at 33 ± 0.47 °C, and released drugs via the Peppas-Sahlin mechanism. Ocular safety was confirmed via in vitro tests using two different cell lines (L929 and Arpe-19), along with in vivo Draize tests, histological examinations, and Hen's Egg Chario-Allontioc-Membrane (HET-CAM) analysis. In vitro studies confirmed the optimized LCM-loaded in-situ gel's suitability for ocular use, demonstrating long-acting effects through controlled release. In addition, ocular irritation and histological studies have supported that it will not show any toxic effect on the eye tissue.

Synergistic enhancement of spinal fusion in preclinical models using low-dose rhBMP-2 and stromal vascular fraction in an injectable hydrogel composite

Spinal fusion surgery remains a significant challenge due to limitations in current bone graft materials, particularly in terms of bioactivity, integration, and safety. This study presents an innovative approach using an injectable hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) hydrogel combined with stromal vascular fraction (SVF) and low-dose recombinant human BMP-2 (rhBMP-2) to enhance osteodifferentiation and angiogenesis. Through a series of in vitro studies and preclinical models involving rats and minipigs, we demonstrated that the hydrogel system enables the sustained release of rhBMP-2, resulting in significantly improved bone density and integration, alongside reduced inflammatory responses. The combination of rhBMP-2 and SVF in this injectable formulation yielded superior spinal fusion outcomes, with enhanced mechanical properties and increased bone mass in both small and large animal models. These findings suggest that this strategy offers a promising and safer alternative for spinal fusion, with strong potential for clinical application.

Advances in adhesive hydrogels applied for ophthalmology: An overview focused on the treatment

Adhesive hydrogels, composed of hydrophilic polymers arranged in a three-dimensional network, have emerged as a pivotal innovation in ophthalmology due to their ability to securely adhere to ocular tissues while providing sustained therapeutic effects. The eye, with its delicate structure and specific needs, presents unique challenges for drug delivery and tissue regeneration. This review explores the transformative potential of adhesive hydrogels in addressing these challenges across a range of ocular conditions, including corneal injuries, cataracts, glaucoma, vitreoretinal disorders, and ocular trauma. By detailing the mechanisms of polymerization and adhesion, this paper highlights how these materials can be customized for specific ophthalmic applications, offering insights into their current use and future possibilities. The emphasis is placed on the clinical significance and future directions of adhesive hydrogels in advancing ophthalmic therapy, potentially revolutionizing the treatment of complex eye diseases.

A Multifunctional Nanozyme Hydrogel with Antibacterial, Antioxidative, and Photo-Induced Nitric Oxide-Supplying Properties for Promoting Infected Wound Healing

Objectives: To design a multifunctional nanozyme hydrogel with antibacterial, photo-responsive nitric oxide-releasing, and antioxidative properties for promoting the healing of infected wounds. Methods: We first developed ultra-small silver nanoparticles (NPs)-decorated sodium nitroprusside-doped Prussian blue (SNPB) NPs, referred to as SNPB@Ag NPs, which served as a multifunctional nanozyme. Subsequently, this nanozyme, together with geniposide (GE), was incorporated into a thermo-sensitive hydrogel, formulated from Poloxamer 407 and carboxymethyl chitosan, creating a novel antibacterial wound dressing designated as GE/SNPB@Ag hydrogel. The physical properties of a GE/SNPB@Ag hydrogel were systematically investigated. Results: After embedding the nanozyme and GE, the resulting GE/SNPB@Ag hydrogel retains its thermosensitive properties and exhibits sustained release characteristics. In addition to its catalase-like activity, the nanozyme demonstrates high photothermal conversion efficiency, photo-induced nitric oxide release, and antibacterial activity. In addition, the hydrogel exhibits favorable antioxidant properties and high biocompatibility. The results of animal experiments demonstrate that the composite hydrogel combined with laser irradiation is an effective method for promoting infected wound healing. Conclusions: In vitro and in vivo studies indicate that the resulting GE/SNPB@Ag hydrogel holds significant potential for the treatment of infected wounds and for further clinical applications.

Sustained-Release Solid Dispersions of Fenofibrate for Simultaneous Enhancement of the Extent and Duration of Drug Exposure

BACKGROUND/OBJECTIVES

A sustained-release formulation of fenofibrate while enhancing drug dissolution with minimal food effect is critical for maximizing the therapeutic benefits of fenofibrate. Therefore, this study aimed to develop an effective solid dispersion formulation of fenofibrate for simultaneous enhancement in the extent and duration of drug exposure.

METHODS

Fenofibrate-loaded solid dispersions (FNSDs) were prepared using poloxamer 407 and Eudragit® RSPO at varied ratios via solvent evaporation. In vitro/in vivo characteristics of FNSDs were examined in comparison with untreated drugs.

RESULTS

Based on dissolution profiles of FNSDs in aqueous media, the weight ratio of fenofibrate: poloxamer 407: Eudragit® RSPO at 1:1:4 (FNSD2) was selected as the optimal composition for achieving sustained drug release while maximizing the drug dissolution. The enhanced and sustained drug release of FNSD2 was also confirmed in a buffer transition system mimicking the pH change in the gastrointestinal tract. FNSD2 achieved approximately 66% drug release over 12 h, while pure drug exhibited only 12%. Furthermore, FNSD2 maintained similar release rates under fed and fasted conditions, while the entire drug dissolution slightly increased in the fed state. Structural analysis by x-ray diffraction showed that fenofibrate remained crystalline in FNSD2. Pharmacokinetic studies in rats revealed that orally administered FNSD2 significantly improved the extent and duration of systemic drug exposure. Compared to pure drugs, the FNSD2 formulation increased the oral bioavailability of fenofibrate by 22 folds with the delayed Tmax of 4 h in rats.

CONCLUSION

FNSD2 formulation is effective in improving the extent and duration of drug exposure simultaneously.

A silver lining in MRSA treatment: The synergistic action of poloxamer-stabilized silver nanoparticles and methicillin against antimicrobial resistance

BACKGROUND

Increasing antibiotic resistance in bacterial infections, including drug-resistant strains like methicillin-resistant Staphylococcus aureus (MRSA), necessitates innovative therapeutic solutions. Silver nanoparticles are promising for combating infections, but toxicity concerns emphasize the importance of factors like dosage, size, shape, and surface chemistry. Hence, exploring poloxamer as a stabilizing agent to reduce its toxicity and enhance the antibacterial effect on MRSA is investigated.

METHODS

Silver nanoparticles stabilized with poloxamer (AgNPs@Pol) were synthesized through the chemical reduction method and characterized using UV-visible spectrophotometer, HR-TEM, DLS, and Zeta potential measurements. Subsequently, the antibacterial activity of AgNPs@Pol alone and in combination with methicillin against MRSA and methicillin-susceptible S. aureus (MSSA) was evaluated using the broth microdilution method.

RESULTS

AgNPs@Pol showed significant efficacy against MRSA and MSSA, achieving a 100 % reduction in colony-forming units (CFU) at 9.7 μg/ml. The minimum inhibitory concentration (MIC) against MRSA and MSSA was 8.6 μg/ml and 4.3 μg/ml, respectively. A synergistic effect was observed when AgNPs@Pol was combined with methicillin. Treatment with AgNPs@Pol increased reactive oxygen species (ROS) production in both strains, contributing to its antibacterial activity. Real-time qPCR analysis indicated the downregulation of genes involved in antimicrobial resistance and cell adhesion in both strains. Further, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay demonstrated low cytotoxicity for AgNPs@Pol against MCF-7, MG-63, and NIH-3T3 cell lines.

CONCLUSION

The developed AgNPs@Pol demonstrated extensive colloidal stability, potent antibacterial activity and synergistic effect with methicillin against MRSA and MSSA. Further studies in primary cells and in vivo models may validate its potential for clinical applications.

Locally Acting Budesonide-Loaded Solid Self-Microemulsifying Drug Delivery Systems (SMEDDS) for Distal Ulcerative Colitis

Background

Budesonide (BUD) is a BCS class II medication with poor water solubility and limited oral bioavailability. In this study, innovative solid self-microemulsifying drug delivery systems (BUD-SMEDDS) were developed for effective local management of distal ulcerative colitis (UC).

Methods

Based on solubility and emulsification tests, the components of the self-microemulsifying drug delivery system (SMEDDS) were Capryol™ 90, Tween 80, and Transcutol HP. The impacts of BUD-SMEDDS ingredients (as inputs) on the average globule size (AGS), polydispersity index (PDI), and self-emulsification time (SET) as responses were investigated using the Box-Behnken design methodology. Solid rectal systems were then fabricated using the optimized values of SMEDDS components in Lutrol® bases. The developed systems were evaluated for in vitro characteristics and in vivo efficacy using a rat colitis model.

Results

For all responses, the greatest impact was attributed to the oil content of SMEDDS. An optimized BUD-SMEDDS with AGS of 33 ± 2.9 nm, PDI of 0.29 ± 0.03 and SET of 25 ± 2.5 s) was selected for rectal formulations. The developed formulations demonstrated acceptable physical characteristics and mucoadhesive abilities. Differential scanning calorimetric (DSC) analysis revealed the absence of BUD crystallinity in the SMEDDS formulations. The drug release patterns could be regulated by selecting the grade and composition of the incorporated Lutrols. Clinical and histopathological assessments revealed considerable improvements in animals treated with BUD-SMEDDS formulations.

Conclusion

Overall findings confirmed the superior capability of solid SMEDDS as BUD carriers to manage distal colitis in tested animals.

Formulation of Emulgels Containing Clotrimazole for the Treatment of Vaginal Candidiasis

Vaginal candidiasis poses significant health concerns that affect approximately 75% of women globally and often leads to discomfort and a decrease in quality of life. Traditional treatments, despite their effectiveness, may cause discomfort and adverse effects, such as vaginal discharge, bleeding, and dryness, promoting the exploration of alternative formulations. In this study, we aimed to develop a novel therapeutic approach for the treatment of vaginal candidiasis utilizing oleic acid containing emulgels made from thermoresponsive poloxamer-based hydrogels. These emulgels were designed to provide a sustained release of clotrimazole, an antifungal agent. Incorporating oleic acid enhanced the drug's solubility and contributed to vaginal health. The formulations were characterized by their rheological properties, in vitro release, mucoadhesion, and spreadability. We conducted rheological measurements on the hydrogels that served as the base for the emulgels, as well as on the emulgels themselves. The emulgels exhibited continuous rheological behavior with changing temperatures, making them suitable for storage at room temperature. With an increasing HPMC content, we achieved enhanced mucoadhesion, which is beneficial for formulations used in body cavities. Moreover, in vitro release studies revealed sustained drug release profiles, which can be adjusted by varying the ratios of poloxamers and HPMC. These findings suggest that the developed emulgels offer a promising therapeutic option for vaginal candidiasis, addressing both the symptoms and the treatment of discomfort.

Recent progress in nanoparticulate-based intranasal delivery for treating of different central nervous system diseases

Drug administration to the central nervous system (CNS) has become a great obstacle because of several biological barriers, such as the blood-brain barrier, therefore, brain targeting insights are a light for scientists to move forward for treating neurogenerative diseases using advanced non-invasive methods. The current demand is to use a potential direct route as the nasal administration to transport drugs into the brain enhancing the BBB permeability and hence, increasing the bioavailability. Interestingly, recent techniques have been implanted in formulating nanocarriers-based therapeutics for targeting and treating ischemic stroke using lipid or polymeric-based materials. Nanoparticulate delivery systems are set as an effective platform for brain targeting as polymeric nanoparticles and polymeric micelles or nanocarriers based on lipids for preventing drug efflux to promote optimal therapeutic medication concentration in the brain-diseased site. In recent years, there has been a notable increase in research publications and ongoing investigations on the utilization of drug-loading nanocarriers for the treatment of diverse CNS diseases. This review comprehensively depicts these dangerous neurological disorders, drug targeting challenges to CNS, and potential contributions as novel intranasal nano-formulations are being used to treat and regulate a variety of neurological diseases.

Technological Strategies Applied to Pharmaceutical Systems for Intranasal Administration of Drugs Intended for Neurological Treatments: A Review

The complexity of treating neurological diseases has meant that new strategies have had to be developed to deliver drugs to the brain more efficiently and safely. Intranasal drug delivery is characterized by its ease of administration, safety, and rapid delivery directly from the nose to the brain. Several strategies have been developed to improve the delivery of drugs to the brain via nasal administration. These include the use of mucoadhesive and thermoresponsive polymers and their combination into polymer blends, as well as the use of liposomes, niosomes, and nano- and microemulsions. Therefore, this review focuses on technologies for developing pharmaceutical systems aimed at delivery via the nose to the brain, contributing to new treatments for difficult neurological disorders. Some of the most common and difficult-to-treat neurological conditions, the intranasal route of administration, and the anatomy of the nasal cavity have been discussed, as well as factors that may influence the absorption of drugs administered into the nose. The types of intranasal formulations and the devices that can be used to administer these products are also discussed in this review. Strategies for improving the transport of bioactive agents and increasing bioavailability are highlighted. The technologies discussed in this review can facilitate the development of formulations with improved properties, such as drug release and mucoadhesiveness, which have several advantages for patients requiring complex neurological treatments.

Optimizing chemically stable chloramphenicol in-situ gel formulations using poloxamer 407 and HPMC through full-factorial design

The primary goal was to enhance the stability and bioavailability of chloramphenicol for ophthalmic use without compromising patient comfort, such as causing blurry vision. This study employed a 2-level full factorial design to optimize the formulation, exploring different concentrations of poloxamer 407 and HPMC to achieve this objective.

A doxorubicin loaded chitosan-poloxamer in situ implant for the treatment of breast cancer

Breast cancer is a serious concern for many women worldwide. Drug-loaded implants have shown several benefits over systemic administrations. To provide anti-cancer drugs with controlled release and reduced systemic toxicity, biodegradable in situ implants have attracted a lot of attention. In the present study, we aimed to design and optimize a doxorubicin-loaded chitosan-poloxamer in situ implant for breast cancer treatment. Utilizing Box-Behnken Design and a Quality-by-Design (QbD) methodology, the in situ implant was prepared with chitosan (X1), poloxamer 407 concentration (X2), and stirring time (X3) as the independent variables. It was characterized for its in vitro gelation time, pH, rheology, and morphology, and evaluated based on drug release profile, in vitro cytotoxicity activities, in vitro anti-inflammatory potential, in vitro cellular uptake, and in vivo anti-inflammatory and pharmacokinetics to ensure their therapeutic outcomes. The results revealed that the prepared formulation showed a gelation time of 26 ± 0.2 s with a viscosity of 8312.6 ± 114.2 cPs at 37 °C. The developed formulation showed better cytotoxic activity in MCF-7 cell lines compared to the free drug solution. It demonstrated reduced levels of pro-inflammatory cytokines in RAW 264.7 macrophages. Further, the prepared in situ implant increases the intracellular accumulation of DOX in the MCF-7 cells. The in vivo pharmacokinetic investigations depicted an increase in t 1/2 and a decrease in AUC of the developed formulation resulting in prolonged drug release and there could be a lower drug concentration in the bloodstream than for the free drug. Therefore, the developed in situ implant may offer a viable option for breast cancer treatment.

Mitigative Effect and Mechanism of Caffeic Acid Combined with Umbilical Cord-Mesenchymal Stem Cells on LPS-Induced Mastitis

Mastitis is an inflammation of the mammary gland tissue that can lead to decreased milk production and altered milk composition, carrying serious implications for the safety of dairy products. Although both caffeic acid (CA) and umbilical cord-mesenchymal stem cells (UC-MSCs) showed potential anti-inflammatory and immunomodulatory properties, little is known about their combined roles in treating mastitis. Here, we report the combined effects and mechanisms of CA and UC-MSCs on lipopolysaccharide (LPS)-induced mastitis. Based on the network pharmacological analysis, the potential relevant genes involved in the alleviating effects of CA on LPS-induced mastitis were inferred. In LPS-treated mammary epithelial cells, CA or/and UC-MSC conditioned medium (UC-MSC-CM) inhibited the phosphorylation of p65, p50, p38, IκB, and MKK3/6 proteins and the expression of downstream inflammatory factors TNF-α, IL-1β, IL-6, IL-8, and COX-2. Additionally, CA or/and hydrogel-loaded UC-MSCs also suppressed the activation of the above inflammatory pathway, leading to the alleviation of pathological damages in the LPS-induced mouse mastitis model. UC-MSCs exhibited more significant effects than CA, and the combined treatment of both was more effective. Our study sheds light on the synergistic and complementary effects of CA and UC-MSCs in alleviating mastitis, offering clues for understanding the regulation of the p38-MAPK/NF-κB↔TNF-α signal transduction loop in the tumor necrosis factor (TNF) pathway as a potential mechanism. This study provides a theoretical basis for developing a novel antibiotic alternative treatment of mastitis that may contribute to reducing economic losses in animal husbandry and protecting public health safety.

Paroxetine Loaded Nanostructured Lipid Carriers Based In-situ Gel for Brain Delivery via Nasal Route for Enhanced Anti-Depressant Effect: In Vitro Prospect and In Vivo Efficacy

This study focused on developing a thermosensitive gel with nanostructured lipid carriers (NLCs) loaded with paroxetine (PAR) to enhance the treatment and management of depression via nasal administration. Micro emulsion technique was utilized for the PAR-NLCs preparation. The acetyl alcohol and oleic acid were used in the ratio of 76:24. In the NLCs Tween 40, Span40 and Myrj 52 were used as a surfactant. The NLCs were then added into Poloxamer mixture to get thermosensitive NLCs based gel. Characterization, in vitro and in vivo studies were performed to check the efficiency of formulation in drug delivery. The entrapment efficiency of optimized PAR-NLCs was about 90%. The particle size, zeta potential and PDI were 155 ± 1.4 nm, -25.9 ± 0.5 mV, and 0.12 ± 0.01 respectively. The optimized gel showed a gelling temperature of 31.50 ± 0.50°C and a gelling time of 1 ± 0.12 s with a pH of 6, suitable for nasal administration. The in vitro release assay of PAR-NLC-gel showed a cumulative release of about 59% in the first 6 h after comparison with PAR-NLCs which showed almost 100%release. In vivo studies included forced swim test and tail suspension tests showed significant potential for treating depression when compared to PAR-NLCs. PAR-NLCs and NLCs based gel enhanced the tissue architecture and suppressed the expression of TNF-α in brain cortex from histological and immunohistochemical analysis. PAR- NLCs gel-based delivery system can prove to be an effective delivery system for brain targeting through nose for the better management of depression.

Octa-Arginine-Conjugated Liposomal Nimodipine Incorporated in a Temperature-Responsive Gel for Nasoencephalic Delivery

Nimodipine is the primary clinical drug used to treat cerebral vasospasm following subarachnoid hemorrhage. Currently, tablets have low bioavailability when taken orally, and injections contain ethanol. Therefore, we investigated a new method of nimodipine administration, namely, nasoencephalic administration. Nasal administration of nimodipine was carried out by attaching the cell-penetrating peptide octa-arginine (R8) to liposomes of nimodipine and incorporating it into a temperature-sensitive in situ gel. The prepared liposomes and gels underwent separate evaluations for in vitro characterization. In vitro release exhibited a significant slow-release effect. In vitro toad maxillary cilia model, RPMI 2650 cytotoxicity, and in vivo SD rat pathological histotoxicity experiments showed that all the dosage from the groups had no significant toxicity to toad maxillary cilia, RPMI 2650 cells, and SD rat tissues and organs, and the cilia continued to oscillate up to 694 ± 10.15 min, with the survival rate of the cells being above 85%. A transwell nasal mucosa cell model and an isolated porcine nasal mucosa model were established, and the results showed that the osmolality of the R8-modified nimodipine liposomal gel to nasal mucosal cells and isolated porcine nasal mucosa was 30.41 ± 2.14 and 65.9 ± 7.34 μg/mL, respectively, which was significantly higher than that of the NM-Solution and PEGylated nimodipine liposome gel groups. Animal fluorescence imaging studies revealed that the R8-modified nimodipine liposomal gel displayed increased brain fluorescence intensity compared to the normal liposomal gel. Pharmacokinetic results showed that after transnasal administration, the AUC(0-∞) of the R8-modified nimodipine liposomal gel was 11.662 ± 1.97 μg·mL-1, which was significantly higher than that of the plain nimodipine liposomal gel (5.499 ± 2.89 μg·mL-1). Brain-targeting experiments showed that the brain-targeting efficiencies of the PEGylated nimodipine liposome gel and R8-modified PEGylated nimodipine liposome gels were 20.44 and 33.45, respectively, suggesting that R8/PEG/Lip-NM-TSG significantly increased the brain-targeting of the drug.

Synthesis and characterization of injectable thermosensitive hydrogel based on Pluronic-grafted silk fibroin copolymer containing hydroxyapatite nanoparticles as potential for bone tissue engineering

Injectable hydrogels are promising for bone tissue engineering due to their minimally invasive application and adaptability to irregular defects. This study presents the development of pluronic grafted silk fibroin (PF-127-g-SF), a temperature-sensitive graft copolymer synthesized from SF and modified PF-127 via a carbodiimide coupling reaction. The PF-127-g-SF copolymer exhibited a higher sol-gel transition temperature (34 °C at 16 % w/v) compared to PF-127 (23 °C), making it suitable for injectable applications. It also showed improved flexibility and strength, with a yielding point increase from <10 % to nearly 30 %. Unlike PF-127 gel, which degrades within 72 h in aqueous media, the PF-127-g-SF copolymer maintained a stable gel structure for over two weeks due to its robust crosslinked hydrogel network. Incorporating hydroxyapatite nanoparticles (n-HA) into the hydrogel reduced pore size and decreased swelling and degradation rates, extending structural stability to four weeks. Increasing n-HA concentration from 0 % to 20 % reduced porosity from 80 % to 66 %. Rheological studies indicated that n-HA enhanced the scaffold's strength and mechanical properties without altering gelation temperature. Cellular studies with MG-63 cells showed that n-HA concentration influenced cell viability and mineralization, highlighting the scaffold's potential in bone tissue engineering.

Cytotoxicity of Doxorubicin-Curcumin Nanoparticles Conjugated with Two Different Peptides (CKR and EVQ) against FLT3 Protein in Leukemic Stem Cells

A targeted micellar formation of doxorubicin (Dox) and curcumin (Cur) was evaluated to enhance the efficacy and reduce the toxicity of these drugs in KG1a leukemic stem cells (LSCs) compared to EoL-1 leukemic cells. Dox-Cur-micelle (DCM) was developed to improve the cell uptake of both compounds in LSCs. Cur-micelle (CM) was produced to compare with DCM. DCM and CM were conjugated with two FLT3 (FMS-like tyrosine kinase)-specific peptides (CKR; C and EVQ; E) to increase drug delivery to KG1a via the FLT3 receptor (AML marker). They were formulated using a film-hydration technique together with a pH-induced self-assembly method. The optimal drug-to-polymer weight ratios for the DCM and CM formulations were 1:40. The weight ratio of Dox and Cur in DCM was 1:9. DCM and CM exhibited a particle size of 20-25 nm with neutral charge and a high %EE. Each micelle exhibited colloidal stability and prolonged drug release. Poloxamer 407 (P407) was modified with terminal azides and conjugated to FLT3-targeting peptides with terminal alkynes. DCM and CM coupled with peptides C, E, and C + E exhibited a higher particle size. Moreover, DCM-C + E and CM-C + E showed the highest toxicity in KG-1a and EoL-1 cells. Using two peptides likely improves the probability of micelles binding to the FLT3 receptor and induces cytotoxicity in leukemic stem cells.

Poloxamer 407 modified collagen/β-tricalcium phosphate scaffold for localized delivery of alendronate

Systemic administration of alendronate is associated with various adverse reactions in clinical settings. To mitigate these side effects, poloxamer 407 (P-407) modified with cellulose was chosen to encapsulate alendronate. This drug-loaded system was then incorporated into a collagen/β-tricalcium phosphate (β-TCP) scaffold to create a localized drug delivery system. Nuclear magnetic resonance spectrum and rheological studies revealed hydrogen bonding between P-407 and cellulose as well as a competitive interaction with water that contributed to the delayed release of alendronate (ALN). Analysis of the degradation kinetics of P-407 and release kinetics of ALN indicated zero-order kinetics for the former and Fickian or quasi-Fickian diffusion for the latter. The addition of cellulose, particularly carboxymethyl cellulose (CMC), inhibited the degradation of P-407 and prolonged the release of ALN. The scaffold's structure increased the contact area of P-407 with the PBS buffer, thereby, influencing the release rate of ALN. Finally, biocompatibility testing demonstrated that the drug delivery system exhibited favorable cytocompatibility and hemocompatibility. Collectively, these findings suggest that the drug delivery system holds promise for implantation and bone healing applications.

Comparative Study of TPGS and Soluplus Polymeric Micelles Embedded in Poloxamer 407 In Situ Gels for Intranasal Administration

This study aims to highlight the importance of choosing the appropriate co-polymer or co-polymer mixed combinations in order to design value-added nasal dosage forms. Local therapy of upper respiratory tract-related infections, such as nasal rhinosinusitis is of paramount importance, thus advanced local therapeutic options are required. Dexamethasone was encapsulated into three different polymeric micelle formulations: Soluplus or TPGS-only and their mixed combinations. Dynamic light scattering measurements proved that the particles have a micelle size less than 100 nm in monodisperse distribution, with high encapsulation efficiency above 80% and an at least 7-fold water solubility increase. Tobramycin, as an antimicrobial agent, was co-formulated into the in situ gelling systems which were optimized based on gelation time and gelation temperature. The sol-gel transition takes place between 32-35 °C, which is optimally below the temperature of the nasal cavity in a quick manner below 5 min, a suitable strategic criterion against the mucociliary clearance. In vitro drug release and permeability studies confirmed a rapid kinetics in the case of the encapsulated dexamethasone accompanied with a sustained release of tobramycin, as the hydrophilic drug.

Novel Thermosensitive and Mucoadhesive Nasal Hydrogel Containing 5-MeO-DMT Optimized Using Box-Behnken Experimental Design

We present the development and characterization of a nasal drug delivery system comprised of a thermosensitive mucoadhesive hydrogel based on a mixture of the polymers Poloxamer 407, Poloxamer 188 and Hydroxypropyl-methylcellulose, and the psychedelic drug 5-methoxy-N,-N-dimethyltryptamine. The development relied on a 3 × 3 Box-Behnken experimental design, focusing on optimizing gelification temperature, viscosity and mucoadhesion. The primary objective of this work was to tailor the formulation for efficient nasal drug delivery. This would increase contact time between the hydrogel and the mucosa while preserving normal ciliary functioning. Following optimization, the final formulation underwent characterization through an examination of the in vitro drug release profile via dialysis under sink conditions. Additionally, homogeneity of its composition was assessed using Raman Confocal Spectroscopy. The results demonstrate complete mixing of drug and polymers within the hydrogel matrix. Furthermore, the formulation exhibits sustained release profile, with 73.76% of the drug being delivered after 5 h in vitro. This will enable future studies to assess the possibility of using this formulation to treat certain mental disorders. We have successfully developed a promising thermosensitive and mucoadhesive hydrogel with a gelling temperature of around 32 °C, a viscosity close to 100 mPas and a mucoadhesion of nearly 4.20 N·m.

Injectable thermo-sensitive hydrogel enhances anti-tumor potency of engineered Lactococcus lactis by activating dendritic cells and effective memory T cells

Engineered bacteria have shown great potential in cancer immunotherapy by dynamically releasing therapeutic payloads and inducing sustained antitumor immune response with the crosstalk of immune cells. In previous studies, FOLactis was designed, which could secret an encoded fusion protein of Fms-related tyrosine kinase 3 ligand and co-stimulator OX40 ligand, leading to remarkable tumor suppression and exerting an abscopal effect by intratumoral injection. However, it is difficult for intratumoral administration of FOLactis in solid tumors with firm texture or high internal pressure. For patients without lesions such as abdominal metastatic tumors and orthotopic gastric tumors, intratumoral injection is not feasible and peritumoral maybe a better choice. Herein, an engineered bacteria delivery system is constructed based on in situ temperature-sensitive poloxamer 407 hydrogels. Peritumoral injection of FOLactis/P407 results in a 5-fold increase in the proportion of activated DC cells and a more than 2-fold increase in the proportion of effective memory T cells (TEM), playing the role of artificial lymph island. Besides, administration of FOLactis/P407 significantly inhibits the growth of abdominal metastatic tumors and orthotopic gastric tumors, resulting in an extended survival time. Therefore, these findings demonstrate the delivery approach of engineered bacteria based on in situ hydrogel will promote the efficacy and universality of therapeutics.

Modeling, the Optimization of the Composition of Emulgels with Ciclopirox Olamine, and Quality Assessment

The design and development of pharmaceutical products require specific knowledge, time, and investment. Response surface methodology (RSM) is a widely used technique in the design of experiments (DoE) to optimize various processes and products. The aim of this study was to model and produce experimental emulgels containing 1% ciclopirox olamine and to evaluate their physical, rheological, and mechanical properties and their ability to release ciclopirox olamine. The objective was to optimize the composition of the experimental emulgel containing 1% ciclopirox olamine by applying a central composite design based on selected criteria. The surfactant (polysorbate 80) had the greatest influence on the physical, rheological, and mechanical properties of the emulgels, as well as on the release of ciclopirox olamine from these systems. During the optimization process, an emulgel of optimal composition was generated containing 38.27% mineral oil, 6.56% polysorbate 80, and 55.17% hydrogel containing 1% ciclopirox olamine, meeting specified criteria (dependent variables) including the maximum flux of ciclopirox olamine, the minimum sol-gel transition temperature (Tsol/gel), and the minimum particle size of the oil phase. The oil phase particle size (D50) of this emulgel was determined to be 0.337 µm, the system Tsol/gel was 9.1 °C, and the flux of ciclopirox olamine from this gel matrix was calculated to be 1.44 mg/cm2. This emulgel of optimal composition could be used to treat fungal skin diseases.

Incorporation of Resveratrol-Hydroxypropyl-β-Cyclodextrin Complexes into Hydrogel Formulation for Wound Treatment

Resveratrol could be applied in wound healing therapies because of its antioxidant, anti-inflammatory and antibacterial effects. However, the main limitation of resveratrol is its low aqueous solubility. In this study, resveratrol was included in hydroxypropyl-β-cyclodextrin complexes and further formulated in Pluronic F-127 hydrogels for wound treatment therapy. IR-spectroscopy and XRD analysis confirmed the successful incorporation of resveratrol into complexes. The wound-healing ability of these complexes was estimated by a scratch assay on fibroblasts, which showed a tendency for improvement of the effect of resveratrol after complexation. The antimicrobial activity of resveratrol in aqueous dispersion and in the complexes was evaluated on methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, and Candida albicans strains. The results revealed a twofold decrease in the MIC and stronger inhibition of the metabolic activity of MRSA after treatment with resveratrol in the complexes compared to the suspended drug. Furthermore, the complexes were included in Pluronic hydrogel, which provided efficient drug release and appropriate viscoelastic properties. The formulated hydrogel showed excellent biocompatibility which was confirmed via skin irritation test on rabbits. In conclusion, Pluronic hydrogel containing resveratrol included in hydroxypropyl-β-cyclodextrin complexes is a promising topical formulation for further studies directed at wound therapy.

Rheological and Injectability Evaluation of Sterilized Poloxamer-407-Based Hydrogels Containing Docetaxel-Loaded Lipid Nanoparticles

Nanostructured lipid carriers (NLCs) have the potential to increase the bioavailability and reduce the side effects of docetaxel (DTX). However, only a small fraction of nanoparticles given intravenously can reach a solid tumor. In situ-forming gels combined with nanoparticles facilitate local administration and promote drug retention at the tumor site. Injectable hydrogels based on poloxamer 407 are excellent candidates for this hybrid nanoparticle-hydrogel system because of their thermoresponsive behavior and biocompatibility. Therefore, this work aimed to develop injectable poloxamer hydrogels containing NLCs for intratumoral delivery of DTX. To ensure sterility, the obtained hydrogels were autoclaved (121 °C for 15 min) after preparation. Then, the incorporation of NLCs into the poloxamer hydrogels and the impact of steam sterilization on the nanocomposite hydrogels were evaluated concerning sol-gel transition, injectability, and physicochemical stability. All formulations were extruded through the tested syringe-needle systems with acceptable force (2.2-13.4 N) and work (49.5-317.7 N·mm) of injection. Following steam sterilization, injection became easier in most cases, and the physicochemical properties of all hydrogels remained practically unchanged according to the spectroscopical and thermal analysis. The rheological evaluation revealed that the nanocomposite hydrogels were liquid at 25 °C and underwent rapid gelation at 37 °C. However, their sterilized counterparts gelled at 1-2 °C above body temperature, suggesting that the autoclaving conditions employed had rendered these nanocomposite hydrogels unsuitable for local drug delivery.

New synthetic molecules incorporated into polymeric micelles used for treatment against visceral leishmaniasis

Treatment against visceral leishmaniasis (VL) presents problems, mainly related to drug toxicity, high cost and/or by emergence of resistant strains. In the present study, two vanillin synthetic derivatives, 3 s [4-(2-hydroxy-3-(4-octyl-1H-1,2,3-triazol-1-yl)propoxy)-3-methoxybenzaldehyde] and 3 t [4-(3-(4-decyl-1H-1,2,3-triazol-1-yl)-2-hydroxypropoxy)-3-methoxybenzaldehyde], were evaluated as therapeutic candidates in a murine model against Leishmania infantum infection. Molecules were used pure (3 s and 3 t) or incorporated into Poloxamer 407-based micelles (3 s/M and 3 t/M) in the infected animals, which also received amphotericin B (AmpB) or Ambisome® as control. Results showed that 3 s/M and 3 t/M compositions induced a Th1-type immune response in treated animals, with higher levels of IFN-γ, IL-2, TNF-α, IL-12, nitrite, and IgG2a antibodies. Animals presented also low toxicity and significant reductions in the parasite load in their spleens, livers, bone marrows and draining lymph nodes, as compared as control groups mice, with the evaluations performed one and 30 days after the application of the therapeutics. In conclusion, preliminary data suggest that 3 s/M and 3 t/M could be considered for future studies as therapeutic agents against VL.

Phase transforming in situ gels for sustained and controlled transmucosal drug delivery via the intravaginal route

Direct, reliable, controlled, and sustained drug delivery to female reproductive tract (FRT) remains elusive, with conventional dosage forms falling way short of the mark, leading to premature leakage, erratic drug delivery, and loss of compliance. Historically, the intravaginal route remains underserved by the pharmaceutical sector. To comprehensively address this, we turned our focus to phase-transforming sol-gels, using poloxamers, a thermosensitive polymer and, doxycycline (as hyclate salt, DOXH) as our model agent given its potential use in sexually transmitted infections (STIs). We further enhanced mucoadhesiveness through screening of differing viscosity grade hydroxypropyl methyl celluloses (HPMCs). The optimised sol-gels remained gelled at body temperature (<37 °C) and were prepared in buffer aligned to vaginal cavity pH and osmolality. Lead formulations were progressed based on their ability to retain key rheological properties, and acidic pH in the presence of simulated vaginal fluid (SVF). From a shelf-life perspective, DOXH stability, gelation temperature (Tsol-gel), and pH to three months (2-8 °C) was attained. In summary, the meticulously engineered, phase-transforming sol-gels provided sustained mucoretention despite dilution by vaginal fluid, paving the way for localised antimicrobial drug delivery at concentrations that potentially far exceed the minimum inhibitory concentration (MIC) for target STI-causing bacteria of the FRT.

The Use of Additive Manufacturing Techniques in the Development of Polymeric Molds: A Review

The continuous growth of additive manufacturing in worldwide industrial and research fields is driven by its main feature which allows the customization of items according to the customers' requirements and limitations. There is an expanding competitiveness in the product development sector as well as applicative research that serves special-use domains. Besides the direct use of additive manufacturing in the production of final products, 3D printing is a viable solution that can help manufacturers and researchers produce their support tooling devices (such as molds and dies) more efficiently, in terms of design complexity and flexibility, timeframe, costs, and material consumption reduction as well as functionality and quality enhancements. The compatibility of the features of 3D printing of molds with the requirements of low-volume production and individual-use customized items development makes this class of techniques extremely attractive to a multitude of areas. This review paper presents a synthesis of the use of 3D-printed polymeric molds in the main applications where molds exhibit a major role, from industrially oriented ones (injection, casting, thermoforming, vacuum forming, composite fabrication) to research or single-use oriented ones (tissue engineering, biomedicine, soft lithography), with an emphasis on the benefits of using 3D-printed polymeric molds, compared to traditional tooling.

Pharmacological Topical Therapy for Intra-Oral Post Traumatic Trigeminal Neuropathic Pain: A Comprehensive Review

Background: The efficacy of topical treatments in alleviating neuropathic pain is well-established. However, there is a paucity of research on topical interventions designed specifically for intra-oral application, where the tissue composition differs from that of exposed skin. Methods: This comprehensive review endeavors to assess the extant evidence regarding the efficacy of topical treatments in addressing neuropathic pain within the oral cavity. Utilizing combinations of search terms, we conducted a thorough search across standard electronic bibliographic databases-MEDLINE (via PubMed), Embase, Google Scholar, and Up to Date. The variables under scrutiny encompassed topical treatment, local intervention, chronic oral and orofacial pain, and neuropathic pain. All pertinent studies published in the English language between 1992 and 2022 were included in our analysis. Results: Fourteen relevant manuscripts were identified, primarily consisting of expert opinions and case reports. The comprehensive review suggests that topical treatments, especially when applied under a stent, could be effective in mitigating neuropathic pain in the oral area. However, it is crucial to conduct further studies to confirm these preliminary results. The limitations of the reviewed studies, mainly the reliance on expert opinions, small sample sizes, inconsistent study designs, and a lack of long-term follow-up data, highlight the need for more rigorous research. Conclusions: Although initial findings indicate topical treatments may be effective for oral neuropathic pain, the limitations of current studies call for more thorough research. Further comprehensive studies are essential to validate the efficacy of these treatments, standardize procedures, and determine long-term results. This will provide clearer guidance for treating chronic neuropathic pain in the oral cavity.

Gel-Dispersed Nanostructured Lipid Carriers Loading Thymol Designed for Dermal Pathologies

Purpose

Acne vulgaris is one of the most prevalent dermal disorders affecting skin health and appearance. To date, there is no effective cure for this pathology, and the majority of marketed formulations eliminate both healthy and pathological microbiota. Therefore, hereby we propose the encapsulation of an antimicrobial natural compound (thymol) loaded into lipid nanostructured systems to be topically used against acne.

Methods

To address this issue, nanostructured lipid carriers (NLC) capable of encapsulating thymol, a natural compound used for the treatment of acne vulgaris, were developed either using ultrasonication probe or high-pressure homogenization and optimized using 22-star factorial design by analyzing the effect of NLC composition on their physicochemical parameters. These NLC were optimized using a design of experiments approach and were characterized using different physicochemical techniques. Moreover, short-term stability and cell viability using HaCat cells were assessed. Antimicrobial efficacy of the developed NLC was assessed in vitro and ex vivo.

Results

NLC encapsulating thymol were developed and optimized and demonstrated a prolonged thymol release. The formulation was dispersed in gels and a screening of several gels was carried out by studying their rheological properties and their skin retention abilities. From them, carbomer demonstrated the capacity to be highly retained in skin tissues, specifically in the epidermis and dermis layers. Moreover, antimicrobial assays against healthy and pathological skin pathogens demonstrated the therapeutic efficacy of thymol-loaded NLC gelling systems since NLC are more efficient in slowly reducing C. acnes viability, but they possess lower antimicrobial activity against S. epidermidis, compared to free thymol.

Conclusion

Thymol was successfully loaded into NLC and dispersed in gelling systems, demonstrating that it is a suitable candidate for topical administration against acne vulgaris by eradicating pathogenic bacteria while preserving the healthy skin microbiome.

Advances in Hydrogels for Meniscus Tissue Engineering: A Focus on Biomaterials, Crosslinking, Therapeutic Additives

Meniscus tissue engineering (MTE) has emerged as a promising strategy for meniscus repair and regeneration. As versatile platforms, hydrogels have gained significant attention in this field, as they possess tunable properties that allow them to mimic native extracellular matrices and provide a suitable microenvironment. Additionally, hydrogels can be minimally invasively injected and can be adjusted to match the shape of the implant site. They can conveniently and effectively deliver bioactive additives and demonstrate good compatibility with other functional materials. These inherent qualities have made hydrogel a promising candidate for therapeutic approaches in meniscus repair and regeneration. This article provides a comprehensive review of the advancements made in the research on hydrogel application for meniscus tissue engineering. Firstly, the biomaterials and crosslinking strategies used in the formation of hydrogels are summarized and analyzed. Subsequently, the role of therapeutic additives, including cells, growth factors, and other active products, in facilitating meniscus repair and regeneration is thoroughly discussed. Furthermore, we summarize the key issues for designing hydrogels used in MTE. Finally, we conclude with the current challenges encountered by hydrogel applications and suggest potential solutions for addressing these challenges in the field of MTE. We hope this review provides a resource for researchers and practitioners interested in this field, thereby facilitating the exploration of new design possibilities.

A tissue-adhesive F127 hydrogel delivers antioxidative copper-selenide nanoparticles for the treatment of dry eye disease

Dry eye disease (DED) is currently the most prevalent condition seen in ophthalmology outpatient clinics, representing a significant public health issue. The onset and progression of DED are closely associated with oxidative stress-induced inflammation and damage. To address this, an aldehyde-functionalized F127 (AF127) hydrogel eye drop delivering multifunctional antioxidant Cu2-xSe nanoparticles (Cu2-xSe NPs) was designed. The research findings revealed that the Cu2-xSe nanoparticles exhibit unexpected capabilities in acting as superoxide dismutase and glutathione peroxidase. Additionally, Cu2-xSe NPs possess remarkable efficacy in scavenging reactive oxygen species (ROS) and mitigating oxidative damage. Cu2-xSe NPs displayed promising therapeutic effects in a mouse model of dry eye. Detailed investigation revealed that the nanoparticles exert antioxidant, anti-apoptotic, and inflammation-mitigating effects by modulating the NRF2 and p38 MAPK signalling pathways. The AF127 hydrogel eye drops exhibit good adherence to the ocular surface through the formation of Schiff-base bonds. These findings suggest that incorporating antioxidant Cu2-xSe nanoparticles into a tissue-adhesive hydrogel could present a highly effective therapeutic strategy for treating dry eye disease and other disorders associated with reactive oxygen species. STATEMENT OF SIGNIFICANCE: A new formulation for therapeutic eye drops to be used in the treatment of dry eye disease (DED) was developed. The formulation combines copper-selenium nanoparticles (Cu2-xSe NPs) with aldehyde-functionalized Pluronic F127 (AF127). This is the first study to directly examine the effects of Cu2-xSe NPs in ophthalmology. The NPs exhibited antioxidant capabilities and enzyme-like properties. They effectively eliminated reactive oxygen species (ROS) and inhibited apoptosis through the NRF2 and p38 MAPK signalling pathways. Additionally, the AF127 hydrogel enhanced tissue adhesion by forming Schiff-base links. In mouse model of DED, the Cu2-xSe NPs@AF127 eye drops demonstrated remarkable efficacy in alleviating symptoms of DED. These findings indicate the potential of Cu2-xSe NPs as a readily available and user-friendly medication for the management of DED.

Formulation of Budesonide-Loaded Polymeric Nanoparticles into Hydrogels for Local Therapy of Atopic Dermatitis

Budesonide is a mineral corticoid applied in the local therapy of pediatric atopic dermatitis. Unfortunately, its dermal administration is hindered by the concomitant adverse effects and its physicochemical properties. The characteristic pH change in the atopic lesions can be utilized for the preparation of a pH-sensitive nanocarrier. In this view, the formulation of Eudragit L 100 nanoparticles as a budesonide delivery platform could provide more efficient release to the desired site, improve its penetration, and subsequently lower the undesired effects. In this study, budesonide-loaded Eudragit L100 nanoparticles were prepared via the nanoprecipitation method (mean diameter 57 nm, -31.2 mV, and approx. 90% encapsulation efficiency). Their safety was proven by cytotoxicity assays on the HaCaT keratinocyte cell line. Further, the drug-loaded nanoparticles were incorporated into two types of hydrogels based on methylcellulose or Pluronic F127. The formulated hydrogels were characterized with respect to their pH, occlusion, rheology, penetration, spreadability, and drug release. In conclusion, the developed hydrogels containing budesonide-loaded nanoparticles showed promising potential for the pediatric treatment of atopic dermatitis.

A new approach for the treatment of Alzheimer's disease: insulin-quantum dots

The potential use of insulin supplementation for Alzheimer's Disease (AD) was aimed to investigate and explore CQDs as an alternative delivery system. CQDs were produced by microwave and characterised. Insulin-loaded Ins-CQDs and in-situ Gel-Ins-CQDs were developed. The in vitro release kinetics, penetrations of insulin through excised sheep nasal mucosa were determined. Toxicity of CQDs were calculated on SH-SY5Y cells. The stability and usability of the prepared formulations were assessed. The insulin release from the solution was 70.75% after 3 hours, while it was 37.51% for in-situ Gel-Ins-CQDs. IC50 value was 52 µM. The mean particle diameters of Ins-CQDs and in-situ Gel-Ins-CQDs varied between 8.35 ± 0.19 to 8.75 ± 0.03 nm during a 6-month period. Zeta potentials ranged from -31.51 ± 1.39 to -24.43 ± 0.26 mV, and PDI values were between 9.8 ± 0.01 to 5.3 ± 3.2%(SD, n = 3) for Ins-CQDs and in-situ Gel-Ins-CQDs, respectively.Our results show that Gel-Ins-CQDs represented a controlled release over time and can be used for AD through the nasal route.

Stimulus-Responsive Hydrogels as Drug Delivery Systems for Inflammation Targeted Therapy

Deregulated inflammations induced by various factors are one of the most common diseases in people's daily life, while severe inflammation can even lead to death. Thus, the efficient treatment of inflammation has always been the hot topic in the research of medicine. In the past decades, as a potential biomaterial, stimuli-responsive hydrogels have been a focus of attention for the inflammation treatment due to their excellent biocompatibility and design flexibility. Recently, thanks to the rapid development of nanotechnology and material science, more and more efforts have been made to develop safer, more personal and more effective hydrogels for the therapy of some frequent but tough inflammations such as sepsis, rheumatoid arthritis, osteoarthritis, periodontitis, and ulcerative colitis. Herein, from recent studies and articles, the conventional and emerging hydrogels in the delivery of anti-inflammatory drugs and the therapy for various inflammations are summarized. And their prospects of clinical translation and future development are also discussed in further detail.

Nanostrategy of Targeting at Embryonic Trophoblast Cells Using CuO Nanoparticles for Female Contraception

Effective contraceptives have been comprehensively adopted by women to prevent the negative consequences of unintended pregnancy for women, families, and societies. With great contributions of traditional hormonal drugs and intrauterine devices (IUDs) to effective female contraception by inhibiting ovulation and deactivating sperm, their long-standing side effects on hormonal homeostasis and reproductive organs for females remain concerns. Herein, we proposed a nanostrategy for female contraceptives, inducing embryonic trophoblast cell death using nanoparticles to prevent embryo implantation. Cupric oxide nanoparticles (CuO NPs) were adopted in this work to verify the feasibility of the nanostrategy and its contraceptive efficacy. We carried out the in vitro assessment on the interaction of CuO NPs with trophoblast cells using the HTR8/SVneo cell line. The results showed that the CuO NPs were able to be preferably uptaken into cells and induced cell damage via a variety of pathways including oxidative stress, mitochondrial damage, DNA damage, and cell cycle arrest to induce cell death of apoptosis, ferroptosis, and cuproptosis. Moreover, the key regulatory processes and the key genes for cell damage and cell death caused by CuO NPs were revealed by RNA-Seq. We also conducted in vivo experiments using a rat model to examine the contraceptive efficacy of both the bare CuO NPs and the CuO/thermosensitive hydrogel nanocomposite. The results demonstrated that the CuO NPs were highly effective for contraception. There was no sign of disrupting the homeostasis of copper and hormone, or causing inflammation and organ damage in vivo. In all, this nanostrategy exhibited huge potential for contraceptive development with high biosafety, efficacy, clinical translation, nonhormonal style, and on-demand for women.

Sustained delivery of triamcinolone acetonide from a thermosensitive microemulsion gel system for the treatment of sensorineural hearing loss

Intratympanic administration for the delivery of steroids has been extensively studied but limited because of low permeability of the drug through the row window membrane. Here, to effectively deliver poorly soluble triamcinolone acetonide (TA), microemulsions (ME) were prepared from Capmul MCM (oil), Cremophor RH40 (surfactant), and tetraglycol (cosurfactant) based on solubility studies, emulsifying ability test, and pseudoternary phase diagrams. Microemulsion gel (MEG) was prepared by mixing TA-ME with a poloxamer hydrogel base. The physicochemical properties of ME and MEG formulations were characterized, and the toxicity and oto-protective effectiveness were evaluated in vitro and in vivo. The ME-3 formulation showed a small droplet size (16.5 ± 0.2 nm), narrow PDI (0.067 ± 0.041), and enhanced TA solubility (2619.7 ± 57.6 μg/g). The optimized MEG demonstrated temperature-dependent gelation with a gelation time of 208 ± 10 sec at 37 °C. Slow degradation of the gel matrix sustained release of TA from MEG compared to the ME formulation. Both TA-ME and TA-MEG were found to be nontoxic to NIH3T3 cells at the test concentrations (0 to 5 µg/mL), and biocompatible after intratympanic administration to mice. The incorporation of ME into thermosensitive hydrogels prolonged retention of TA at the site of administration until 6 days. As a consequence, the enhanced drug absorption into the cochlea in TA-MEG group (approximately 2 times higher than other groups) protected hair cells, spiral ganglion neurons, and stria vascular cells from cisplatin-induced damage. Therefore, this injectable TA-loaded MEG is an effective and safe vehicle for the sustained delivery of triamcinolone acetonide into the inner ear.

Development and characterization of a poloxamer hydrogel composed of human mesenchymal stromal cells (hMSCs) for reepithelization of skin injuries

Wound healing is a natural physiological reaction to tissue injury. Hydrogels show attractive advantages in wound healing not only due to their biodegradability, biocompatibility and permeability but also because provide an excellent environment for cell migration and proliferation. The main objective of the present study was the design and characterization of a hydrogel loaded with human mesenchymal stromal cells (hMSCs) for use in would healing of superficial skin injures. Poloxamer 407® was used as biocompatible biomaterial to embed hMSCs. The developed hydrogel containing 20 % (w/w) of polymer resulted in the best formulation with respect to physical, mechanical, morphological and biological properties. Its high swelling capacity confirmed the hydrogel's capacity to absorb wounds' exudate. LIVE/DEAD® assay confirm that hMSCs remained viable for at least 48 h when loaded into the hydrogels. Adding increasing concentrations of hMSCs-loaded hydrogel to the epithelium did not affect keratinocytes' viability and healing capacity and all wound area was closed in less than one day. Our study opens opportunities to exploit poloxamer hydrogels as cell carriers for the treatment of skin superficial wound.