Insulin-loaded nanoparticles are prepared by alginate ionotropic pre-gelation followed by chitosan polyelectrolyte complexation

Polyelectrolytes for Environmental, Agricultural, and Medical Applications

In recent decades, polyelectrolytes (PELs) have attracted significant interest owing to a surge in research dedicated to the development of new technologies and applications at the biological level. Polyelectrolytes are macromolecules of which a substantial portion of the constituent units contains ionizable or ionic groups. These macromolecules demonstrate varied behaviors across different pH ranges, ionic strengths, and concentrations, making them fascinating subjects within the scientific community. The aim of this review is to present a comprehensive survey of the progress in the application studies of polyelectrolytes and their derivatives in various fields that are vital for the advancement, conservation, and technological progress of the planet, including agriculture, environmental science, and medicine. Through this bibliographic review, we seek to highlight the significance of these materials and their extensive range of applications in modern times.

Synthesis and characterisation of Mānuka and rosemary oil-based nano-entities and their application in meat

Mānuka (MO) and rosemary oils (RO) -containing nanoemulsions and nanocapsules made of sodium alginate and whey protein, were designed and compared for their antioxidant effect. Mānuka oil-nanoemulsions and nanocapsules had smaller particle sizes (343 and 330 nm), less negative zeta potential (-12 mV and -10 mV), higher phenolic content, and antiradical characteristics than RO-nano-entities. However, nano-entities of both oils showed more thermostability and sustained release than free oils. Further, the antioxidant effect of essential oils and their nano-entities was compared against sodium nitrite (SN)-added and without antioxidants-added (controls) and Wagyu and crossbred beef pastes (14 days refrigerated storage). No significant difference among MO, RO and their nano-entities was noticed in crossbred pastes, while in Wagyu, nanoemulsions showed the lowest oxidation values than controls and SN-added pastes. Hence, nano-entities can be alternatives to chemical preservatives as natural antioxidants in meat preservation, along with improved thermal stability and release than free oils.

Production and investigation of Pickering emulsion stabilised by casein-Qodume Shirazi (Alyssum homolocarpum) seed gum complex particles: gastrointestinal digestion

Recently, there has been growing research interests in designing Pickering emulsions. In this work, Alyssum homolocarpum seed gum (AHSG) and casein protein (CP) nanoparticles (NPs) fabricated as Pickering stabilizers. AHSG (0.0, 0.05, 0.10, and 0.15% (w/w))-CP (2% (w/w)) nanoparticles were fabricated and their properties were investigated (mean diameter, morphology, zeta potential, Fourier transform infra-red, and contact angle). Formation and stability of Pickering emulsion (Pes) stabilized by AHSG-CP NPs were monitored by mean diameter, rheological properties, and in vitro digestion. AHSG-CP Nps exhibited a small size (107.75 ± 0.42-201.52 ± 0.70 nm) and had wettability between 64.94 ± 3.44° and 70.92 ± 7.64°. The stability of PEs was greatly improved by 0.05AHSG-CP NPs, even after 30 days of storage, centrifugation, and in vitro digestion, owing to the reinforcement of particle structure at the oil/water interfaces.This study demonstrates that 0.05% (w/w) AHSG-CP NP showed the highest stability during storage and against gastrointestinal digestion which showed its suitability as a fat reducer emulsion structure.

Self-assembled sodium alginate polymannuronate nanoparticles for synergistic treatment of ophthalmic infection and inflammation: Preparation optimization and in vitro/vivo evaluation

Frequent administrations are often needed during the treatment of ocular diseases due to the low bioavailability of the existing eye drops owing to inadequate corneal penetration and rapid drug washout. Herein, sodium alginate polymannuronate (SA) nanocarriers were developed using ionic gelation method that can provide better bioavailability through mucoadhesivity and sustained drug release by binding to the ocular mucus layer. This study disproves the common belief that only the G block of SA participates in the crosslinking reaction during ionic gelation. Self-assembly capability due to the linear flexible structure of the M block, better biocompatibility than G block along with the feasibility of controlling physicochemical characteristics postulate a high potential for designing efficient ocular drug delivery systems. Initially, four crosslinkers of varied concentrations were investigated. Taguchi design of experiment revealed the statistically significant effect of the crosslinker type and concentration on the particle size and stability. The best combination was detected by analyzing the particle size and zeta potential values that showed the desired microstructural properties for ocular barrier penetration. The desired combination was SA-Ca-1 that had particle size within the optimal corneal penetration range, that is 10-200 nm (135 nm). The drug carriers demonstrated excellent entrapment efficiency (∼89 % for Ciprofloxacin and ∼96 % for Dexamethasone) along with a sustained and simultaneous release of dual drug for at least 2 days. The nanoparticles also showed biocompatibility (4 ± 0.6 % hemolysis) and high mucoadhesivity (73 ± 2 % for 0.25 g) which was validated by molecular docking analysis. The prepared formulation was able to reduce the scleral inflammation of the rabbit uveitis models significantly within 3 days. Thus, the eye drop showed remarkable potential for efficient drug delivery leading to faster recovery.

QbD-Assisted Development and Optimization of Doxycycline Hyclate- and Hydroxyapatite-Loaded Nanoparticles for Periodontal Delivery

The current research aims to develop a carrier system for the delivery of a matrix metalloproteinase (MMP) inhibitor along with a bioceramic agent to the periodontal pocket. It is proposed that the present system, if given along with a systemic antibiotic, would be a fruitful approach for periodontitis amelioration. To fulfill the aforementioned objective, a doxycycline hyclate- and hydroxyapatite-adsorbed composite was prepared by a physical adsorption method and successfully loaded inside sodium alginate-chitosan nanoparticles and optimized based on particle size and drug content. Optimized formulation was then subjected to different evaluation parameters like encapsulation efficiency, hydroxyapatite content, ζ potential, surface morphology, in vitro drug release, cell line studies, and stability studies. For the optimized formulation, particle size, polydispersity index (PDI), entrapment efficiency, ζ potential, and drug content were found to be 336.50 nm, 0.23, 41.77%, -13.85 mV, and 14.00%, respectively. The surface morphology of the placebo and adsorbed composite-loaded nanoparticles as observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the spherical shape and rough surface of the particles. In gingival crevicular fluid (GCF) 7.6, a sustained drug release profile was obtained up to 36 h. In vitro % viability studies performed on murine fibroblast cells (NIH3T3) and human periodontal ligament (hPDL) cell lines confirmed the proliferative nature of the formulation. Also, when subjected to stability studies for 4 weeks, particle size, PDI, and drug content did not vary considerably, thereby ensuring the stable nature of nanoparticles. Henceforth, sodium alginate-chitosan nanoparticles appeared to be a good carrier system for doxycycline hyclate and hydroxyapatite for periodontal therapy. If given along with a system antibiotic, the system will serve as a fruitful tool for infection-mediated periodontal regeneration and healing.

Quetiapine Albumin Nanoparticles as an Efficacious Platform for Brain Deposition and Potentially Improved Antipsychotic Activity

Quetiapine (QP) is a second-generation short-acting antipsychotic drug extensively metabolized in the liver, producing pharmacologically inactive metabolites and leading to diminished bioavailability. Therefore, this study aimed to develop an intravenous QP albumin nanoparticles (NPs) system for improving QP antipsychotic activity and brain targeting. QP-loaded albumin NPs were prepared by the desolvation method. The fabricated NPs were characterized in terms of particle size, zeta potential, entrapment efficiency (EE%), and in vitro drug release. In vivo pharmacokinetics and biodistribution in rats were studied. In addition, the antipsychotic activity of the optimized platform was also investigated. Human serum albumin (HSA) concentration, pH, and stirring time were modulated to optimize QP albumin NPs with a particle size of 103.54 ± 2.36 nm and a QP EE% of 96.32 ± 3.98%. In addition, the intravenous administration of QP albumin NPs facilitated QP brain targeting with a 4.9-fold increase in targeting efficiency compared to the oral QP solution. The QP albumin NPs improved the QP antipsychotic activity, indicated by suppressing rats' hypermobility and reducing the QP's extrapyramidal side effects. The obtained results proposed that intravenous QP- NPs could improve QP brain targeting and its antipsychotic efficiency.

Formulation and In-Vitro/Ex-Vivo Characterization of Pregelled Hybrid Alginate-Chitosan Microparticles for Ocular Delivery of Ketorolac Tromethamine

Innovative hybrid chitosan-sodium alginate (Ch-Ag) microparticles (MPs) were fabricated using both the ionic gelation method as well as the pre-gelation technique. The hybrid Ch-Ag MPs were studied for size, zeta potential, morphology, mucoadhesion, in-vitro release, corneal permeation, and ocular irritation using lens and corneal epithelial cell lines. The average particle size ranged from 1322 nm to 396 nm. The zeta potential for the prepared formulations showed an increase with increasing Ch concentrations up to a value of >35 mV; the polydispersity index (PDI) of some optimized MPs was around 0.1. Compared to drug-free MPs, ketorolac-loaded Ch-Ag MPs demonstrated a drug proportion-dependent increase in their size. SEM, as well as TEM of KT-loaded MPs, confirmed that the formed particles were quasi-spherical to elliptical in shape. The KT release from the MPs demonstrated a prolonged release profile in comparison to the control KT solution. Further, mucoadhesion studies with porcine mucin revealed that the KT-loaded MPs had effective mucoadhesive properties, and polymeric particles were stable in the presence of mucin. Corneal permeation was studied on bovine eyes, and the results revealed that Ch-based MPs were capable of showing more sustained KT release across the cornea compared with that for the control drug solution. Conclusively, the cytotoxicity assay confirmed that the investigated MPs were non-irritant and could confer protection from direct drug irritation of KT on the ocular surface. The MTT cytotoxicity assay confirmed that KT-loaded MPs showed acceptable and reasonable tolerability with both human lens and corneal epithelial cell lines compared to the control samples.

Chitosan/Albumin Coating Factorial Optimization of Alginate/Dextran Sulfate Cores for Oral Delivery of Insulin

The design of nanoparticle formulations composed of biopolymers, that govern the physicochemical properties of orally delivered insulin, relies on improving insulin stability and absorption through the intestinal mucosa while protecting it from harsh conditions in the gastrointestinal (GI) tract. Chitosan/polyethylene glycol (PEG) and albumin coating of alginate/dextran sulfate hydrogel cores are presented as a multilayer complex protecting insulin within the nanoparticle. This study aims to optimize a nanoparticle formulation by assessing the relationship between design parameters and experimental data using response surface methodology through a 3-factor 3-level optimization Box–Behnken design. While the selected independent variables were the concentrations of PEG, chitosan and albumin, the dependent variables were particle size, polydispersity index (PDI), zeta potential, and insulin release. Experimental results showed a nanoparticle size ranging from 313 to 585 nm, with PDI from 0.17 to 0.39 and zeta potential ranging from −29 to −44 mV. Insulin bioactivity was maintained in simulated GI media with over 45% cumulative release after 180 min in a simulated intestinal medium. Based on the experimental responses and according to the criteria of desirability on the experimental region’s constraints, solutions of 0.03% PEG, 0.047% chitosan and 1.20% albumin provide an optimum nanoparticle formulation for insulin oral delivery.

Nanoparticles in Drug Delivery: From History to Therapeutic Applications

Current research into the role of engineered nanoparticles in drug delivery systems (DDSs) for medical purposes has developed numerous fascinating nanocarriers. This paper reviews the various conventionally used and current used carriage system to deliver drugs. Due to numerous drawbacks of conventional DDSs, nanocarriers have gained immense interest. Nanocarriers like polymeric nanoparticles, mesoporous nanoparticles, nanomaterials, carbon nanotubes, dendrimers, liposomes, metallic nanoparticles, nanomedicine, and engineered nanomaterials are used as carriage systems for targeted delivery at specific sites of affected areas in the body. Nanomedicine has rapidly grown to treat certain diseases like brain cancer, lung cancer, breast cancer, cardiovascular diseases, and many others. These nanomedicines can improve drug bioavailability and drug absorption time, reduce release time, eliminate drug aggregation, and enhance drug solubility in the blood. Nanomedicine has introduced a new era for drug carriage by refining the therapeutic directories of the energetic pharmaceutical elements engineered within nanoparticles. In this context, the vital information on engineered nanoparticles was reviewed and conferred towards the role in drug carriage systems to treat many ailments. All these nanocarriers were tested in vitro and in vivo. In the coming years, nanomedicines can improve human health more effectively by adding more advanced techniques into the drug delivery system.

Biopolymeric nanocarrier: an auspicious system for oral delivery of insulin

Subcutaneous administration of insulin has been practiced for the clinical supervision of diabetes pathogenesis but it is often ineffective to imitate the glucose homeostasis and is always invasive. Therefore, it causes patient discomfort and infection of local tissue. These issues lead to finding an alternative route for insulin delivery that could be effective, promising, and non-invasive. However, delivery of insulin orally is the most suitable route but the rapid breakdown of insulin by the gastrointestinal enzymes becomes a major barrier to this method. Therefore, nanocarriers (which guard insulin against degradation and facilitate its uptake) are preferred for oral insulin delivery. Among various categories of nanocarriers, bio-polymeric nanocarriers draw special attention owing to their hydrophilic, non-toxic, and biodegradable nature. This review provides a detailed overview of insulin-loaded biopolymer-based nanocarriers, which give future direction in the optimization and development of a clinically functional formulation for their effective and safe delivery.

Amygdalin: A Review on Its Characteristics, Antioxidant Potential, Gastrointestinal Microbiota Intervention, Anticancer Therapeutic and Mechanisms, Toxicity, and Encapsulation

Bioactive amygdalin, found in high concentrations in bitter almonds, has been recognized as a symbol of the cyanogenic glycoside chemical organic substance, which was initially developed as a pharmaceutical for treating cancer after being hydrolyzed to hydrogen cyanide (HCN). Regrettably, research has shown that HCN can also damage normal cells, rendering it non-toxic to the human body. Extreme controversy surrounds both in vivo and in vitro studies, making its use risky. This review provides an extensive update on characteristics, antioxidant potential, gastrointestinal microbiota intervention, anticancer therapeutic, mechanisms, toxicity, and encapsulation of amygdalin. Antioxidant, anti-tumor, anti-fibrotic, antiatherosclerosis, anti-inflammatory, immunomodulatory, and analgesic characteristics, and the ability to improve digestive and reproductive systems, neurodegeneration, and cardiac hypertrophy are just some of the benefits of amygdalin. Studies verified the HCN-produced amygdalin to be harmful orally, but only at very high doses. Although intravenous treatment was less effective than the oral method, the oral route has a dose range of 0.6 to 1 g daily. Amygdalin’s toxicity depends heavily on the variety of bacteria in the digestive tract. Unfortunately, there is currently no foolproof method for determining the microbial consortium and providing a safe oral dosage for every patient. Amygdalin encapsulation in alginate-chitosan nanoparticles (ACNPs) is a relatively new area of research. Amygdalin has an enhanced cytotoxic effect on malignant cells, and ACNPs can be employed as an active drug-delivery system to release this compound in a regulated, sustained manner without causing any harm to healthy cells or tissues. In conclusion, a large area of research for a substance that might be the next step in cancer therapy is opened up due to unverified and conflicting data.

Pulmonary drug delivery applications of natural polysaccharide polymer derived nano/micro-carrier systems: A review

Respiratory distress syndrome and pneumothorax are the foremost causes of death as a result of the changing lifestyle and increasing air pollution. Numerous approaches have been studied for the pulmonary delivery of drugs, proteins as well as peptides using meso/nanoparticles, nanocrystals, and liposomes. These nano/microcarrier systems (NMCs) loaded with drug provide better systemic as well as local action. Furthermore, natural polysaccharide-based polymers such as chitosan (CS), alginate (AG), hyaluronic acid, dextran, and cellulose are highly used for the preparation of nanoparticles and delivery of the drug into the pulmonary tract due to their advantageous properties such as low toxicity, high hydrophobicity, supplementary mucociliary clearance, mucoadhesivity, and biological efficacy. These properties ease the delivery of drugs onto the targeted site. Herein, recent advances in the natural polymer-derived NMCs have been reviewed for their transport and mechanism of action into the bronchiolar region as well as the respiratory region. Various physicochemical properties such as surface charge, size of nanocarrier system, surface modifications, and toxicological effects of these nanocarriers in vitro and in vivo are elucidated as well. Furthermore, challenges faced for the preparation of a model NMCs for pulmonary drug delivery are also discoursed.

A β-Sitosterol Encapsulated Biocompatible Alginate/Chitosan Polymer Nanocomposite for the Treatment of Breast Cancer

β−sitosterol is the most abundant type of phytosterol or plant sterol and can be found in various plant dietary sources including natural oils, soy products, and nuts. Numerous studies have demonstrated the potential therapeutic and clinical applications of β−sitosterol including lowering low-density lipoprotein and cholesterol levels, scavenging free radicals in the body, and interestingly, treating and preventing cancer. This study focuses on synthesizing and characterizing β−sitosterol encapsulated Alginate/Chitosan nanoparticles (β−sito−Alg/Ch/NPs) and evaluating their effectiveness in breast cancer treatment and their pharmacokinetic profile in vivo. The synthesized NPs, which incurred a mean size of 25 ± 1 nm, were extensively characterized in vitro for various parameters including surface charge and morphology. The NPs were further analyzed using DSC, FT-IR, thermogravimetry and X-ray diffraction studies. The release of β−sito from NPs was carried out in a bio-relevant medium of pH 7.4 and pH 5.5 and samples were drawn off and analyzed under time frames of 0, 8, 16, 32, 64, 48, 80, and 96 h, and the best kinetic release model was developed after fitting drug release data into different kinetic models. The metabolic activity of MCF-7 cells treated with the prepared formulation was assessed. The radical scavenging potential of β−sito−Alg/Ch/NPs was also studied. The pharmacokinetic parameters including Cmax, Tmax, half-life (t1/2), and bioavailability were measured for β−sito−Alg/Ch/NPs as compared to β−sito−suspension. The β−sito−Alg/Ch/NPs stability was assessed at biological pH 7.4. The % drug release in PBS of pH 7.4 reportedly has shown 41 ± 6% vs. 11 ± 1% from β−sito−Alg/Ch/NPs and β−sito−suspension. In acidic pH 5.5 mimicking the tumor microenvironment has shown 75 ± 9% vs. 12 ± 4% drug release from β−sito−Alg/Ch/NPs and β−sito−suspension. When compared to the β−sito−suspension, the β−sito−Alg/Ch/NPs demonstrated greater cytotoxicity (p < 0.05) and ~3.41-fold higher oral bioavailability. Interestingly, this work demonstrated that β−sito−Alg/Ch/NPs showed higher cytotoxicity due to improved bioavailability and antioxidant potential compared to the β−sito−suspension.

Natural Polysaccharide-Based Nanodrug Delivery Systems for Treatment of Diabetes

In recent years, natural polysaccharides have been considered as the ideal candidates for novel drug delivery systems because of their good biocompatibility, biodegradation, low immunogenicity, renewable source and easy modification. These natural polymers are widely used in the designing of nanocarriers, which possess wide applications in therapeutics, diagnostics, delivery and protection of bioactive compounds or drugs. A great deal of studies could be focused on developing polysaccharide nanoparticles and promoting their application in various fields, especially in biomedicine. In this review, a variety of polysaccharide-based nanocarriers were introduced, including nanoliposomes, nanoparticles, nanomicelles, nanoemulsions and nanohydrogels, focusing on the latest research progress of these nanocarriers in the treatment of diabetes and the possible strategies for further study of polysaccharide nanocarriers.

Phytosterol-Loaded Surface-Tailored Bioactive-Polymer Nanoparticles for Cancer Treatment: Optimization, In Vitro Cell Viability, Antioxidant Activity, and Stability Studies

This study aimsto optimize, characterize, and assess the phytosterol-loaded surface-tailored bioactive Alginate/Chitosan NPs for antitumor efficacy against breast cancer. β-Sitosterol-loaded Alginate/Chitosan nanoparticles (β-SIT-Alg/Ch-NPs) were fabricated using an ion-gelation technique, and then the NPs’ surfaces were activated using an EDC/sulfo-NHS conjugation reaction. The activated chitosan NPs werefunctionalized with folic acid (FA), leveled as β-SIT-Alg/Ch-NPs-FA. Moreover, the functionalized NPs were characterized for size distribution, polydispersity index (PDI), and surface charge, FT-IR and DSC. β-SIT released from β-SIT-Alg/Ch-NPs was estimated in various biorelevant media of pH 7.4, 6.5, and 5.5, and data werefitted into various kinetic models. The cytotoxic study of β-SIT-Alg/Ch-NPs-FA against the cancer cell line was established. The antioxidant study of developed β-SIT-Alg/Ch-NPs was performed using DPPH assay. The stability of developed optimized formulation was assessed in phosphate buffer saline (PBS, pH 7.4), as per ICH guidelines. The drug-entrapped Alg/Ch-NPs-FA appeared uniform and nonaggregated, and the nanoscale particle measured a mean size of 126 ± 8.70 nm. The %drug encapsulation efficiency and %drug loading in β-SIT-Alg/Ch-NPs-FA were 91.06 ± 2.6% and 6.0 ± 0.52%, respectively. The surface charge on β-SIT-Alg/Ch-NPs-FA was measured as +25 mV. The maximum β-SIT release from β-SIT-Alg/Ch-NPs-FA was 71.50 ± 6.5% in pH 5.5. The cytotoxic assay expressed an extremely significant antitumor effect by β-SIT-Alg/Ch-NPs-FA when compared to β-SIT-suspension (p < 0.001). The antioxidant capacity of β-SIT-Alg/Ch-NPs-FA was 91 ± 5.99% compared to 29 ± 8.02% for β-SIT-suspension. The stability of NPs noticed an unworthy alteration (p > 0.05) in particle sizes and other parameters under study in the specific period.

pH Responsive Abelmoschus esculentus Mucilage and Administration of Methotrexate: In-Vitro Antitumor and In-Vivo Toxicity Evaluation

The rapid progression in biomaterial nanotechnology apprehends the potential of non-toxic and potent polysaccharide delivery modules to overcome oral chemotherapeutic challenges. The present study is aimed to design, fabricate and characterize polysaccharide nanoparticles for methotrexate (MTX) delivery. The nanoparticles (NPs) were prepared by Abelmoschus esculentus mucilage (AEM) and chitosan (CS) by the modified coacervation method, followed by ultra-sonification. The NPs showed much better pharmaceutical properties with a spherical shape and smooth surface of 213.4–254.2 nm with PDI ranging between 0.279–0.485 size with entrapment efficiency varying from 42.08 ± 1.2 to 72.23 ± 2.0. The results revealed NPs to possess positive zeta potential and a low polydispersity index (PDI). The in-vitro drug release showed a sustained release of the drug up to 32 h with pH-dependence. Blank AEM -CS NPs showed no in-vivo toxicity for a time duration of 14 days, accompanied by high cytotoxic effects of optimized MTX loaded NPs against MCF-7 and MD-MBA231 cells by MTT assay. In conclusion, the findings advocated the therapeutic potential of AEM/CS NPs as an efficacious tool, offering a new perspective for pH-responsive routing of anticancer drugs with tumor cells as a target.

Nanoencapsulation of saffron crocin into chitosan/alginate interpolyelectrolyte complexes for oral delivery: A Taguchi approach to design optimization

Crocin, as a nutraceutical component of saffron (Crocus sativus L.), possesses numerous therapeutic effects. In the current study, a crocin-loaded chitosan/alginate (CS/ALG) nanocarrier was developed for oral delivery. The influence of preparation variables including pH and the concentrations of CS, ALG, and calcium chloride (CaCl₂ ) on encapsulation efficiency (EE%) and loading efficiency (LE%) of CS/ALG nanoparticles (NPs) was evaluated by L9 Taguchi orthogonal array (OA). The results showed that at 0.25% w/v CS, 0.1% w/v ALG, pH 4.5, and absence of CaCl₂ , crocin was loaded into CS/ALG NPs with EE% and LE% of 91.5% and 27.4%, respectively. Ultrasonication reduced the particle sizes (PSs) up to 100 nm, and freeze-dried NPs reproduced the particles with average size of 90 nm. Scanning electron microscopy (SEM) was successfully used to characterize the structure and morphology of freeze-dried NPs, confirming very fine NPs having sizes less than 100 nm. Crocin loaded into NPs showed higher stability in simulated gastric pH 2 compared to free crocin (2.1% and 7.5% degradation at 60 min, respectively). Furthermore, a pH-dependent sustained crocin release was observed with faster release at pH 2. Overall, the very small PS along with high encapsulation efficiency and stability can enhance crocin oral bioavailability making CS/ALG nanovehicles promising as an effective delivery system. PRACTICAL APPLICATION: Crocin as a functional component of Saffron is not sufficiently stable in gastrointestinal tract and its absorption is not complete. Chitosan/Alginate nanoparticles can encapsulate it efficiently, protect it and enhance its absorption orally. The availability and simplicity of the materials and equipments employed in current research provide the possibility to industrial scale up of the Crocin nanoparticles.

Preparation, characterization and releasing property of antibacterial nano-capsules composed of ε-PL-EGCG and sodium alginate-chitosan

Aquatic products with high moisture and protein content are susceptible to bacterial growth and spoilage. Searching for efficient and safe natural antibacterial agents to preserve aquatic products has been concerned widely. In this study, ε-poly-lysine-epigallocatechin gallate/sodium alginate-chitosan nanoparticles (ε-PL-EGCG/SA-CS NPs) were prepared using sodium alginate and chitosan as wall materials and ε-PL-EGCG as core material. The size of nanoparticles was about 200 nm and the encapsulation efficiency was 78.2%. Transmission electron microscopy (TEM) images confirmed the prepared spherical nanoparticles. Fourier transform infrared spectroscopy (FTIR) and multifunctional polycrystalline X-ray diffraction (XRD) spectra indicated that ε-PL-EGCG was encapsulated in the nanoparticles. Thermo-gravimetric analysis (TGA) illustrated that the thermal stability of encapsulated ε-PL-EGCG was improved more than that of bare ε-PL-EGCG. In addition, in vitro release assays showed that the ε-PL-EGCG was released continuously over 36 h. Bacteria inhibition results showed that the ε-PL-EGCG/SA-CS NPs significantly inhibited specific spoilage bacteria E3 that screened out of aquatic products, Escherichia coli and Staphylococcus aureus. In conclusion, ε-PL-EGCG/SA-CS NPs are an effective antibacterial means with wide application prospects in the field of aquatic products preservation.

Sialic Acid Conjugated Chitosan Nanoparticles: Modulation to Target Tumour Cells and Therapeutic Opportunities

Targeted delivery of therapeutics forestalls the dreadful delocalized effects, drug toxicities and needless immunosuppression. Cancer cells are bounteous with sialic acid and the differential expression of glycosyl transferase, glycosidase and monosaccharide transporter compared to healthy tissues. The current study entails the development and characterisation of sialic acid (SA)-labelled chitosan nanoparticles encapsulating gemcitabine (GEM). Chitosan (CS) was conjugated with SA using coupling reaction and characterised spectroscopically. Furthermore, different concentrations of chitosan and tripolyphosphate (TPP) were optimised to fabricate surface modified chitosan nanoparticles. SA conjugated chitosan nanoparticles encapsulating GEM (SA-CS_GEM NPs) of 232 ± 9.69 nm with narrow distribution (PDI < 0.5) and zeta potential of - 19 ± 0.97 mV was fabricated. GEM was successfully loaded in the SA-CS NPs, depicting prolonged and biphasic drug release pattern more elated at low pH. Pronounced cellular uptake (FITC tagged) and cytotoxicity (IC₅₀ 487.4 nM) was observed in SA-CS_GEM NPs against A549 cells. IC₅₀ for SA-CS_GEM NPs plunged with an increase in the time points from 24 to 72 h. Concentration-dependent haemolytic study confirmed significant haemocompatibility of SA-CS_GEM NPs. Pharmacokinetic study was performed on Sprague-Dawley rats and the kinetic parameters were calculated using PKSolver 2.0. Results demonstrated a consequential refinement of 2.98 times in modified SA-CS_GEM NPs with a significant increase in retention time, bioavailability and elimination half-life, and decrease in elimination rate constant and volume of distribution in comparison to CS_GEM NPs. Therefore, SA-CS shell core nanoparticles could be a beneficial approach to target and treat NSCLC (non-small cell lung cancer) and direct for research possibilities to target the other tumour cells.

Novel strategies to oral delivery of insulin: Current progress of nanocarriers for diabetes management

Diabetes mellitus is one of the most serious public health problems in the world. Repeated daily injections of subcutaneous insulin is the standard treatment for patients with type 1 diabetes mellitus; however, subcutaneous insulin injections can potentially cause local discomfort, patient noncompliance, hypoglycemia, failure to regulate glucose homeostasis, infections, and fat deposits at the injection sites. In recent years, numerous attempts have been made to produce safe and efficient nanoparticles for oral insulin delivery. Oral administration is considered the most effective alternative route to insulin injection, but it is accompanied by several challenges related to enzymatic proteolysis, digestive breakdown, and absorption barriers. A number of natural and synthetic polymeric, lipid-based, and inorganic nanoparticles have been investigated for use. Although improvements have recently been made in potential oral insulin delivery systems, these require further investigation before clinical trials are conducted. In this review, new approaches to oral insulin delivery for diabetes treatment are discussed, including polymeric, lipid-based, and inorganic nanoparticles, as well as the clinical trials performed for this purpose.

Chitosan for biomedical applications, promising antidiabetic drug delivery system, and new diabetes mellitus treatment based on stem cell

Since chitosan's excellent pharmacokinetic and chemical properties, it is an attractive and promising carbohydrate biopolymer in biomedical applications. Chitosan's beneficial function in the defense and propagation of pancreatic β cells, reducing hyperglycemia, and avoiding diabetes mellitus associated with impaired lipid metabolism has been demonstrated in several studies. Additionally, chitosan has also been used in various nanocarriers to deliver various antidiabetic drugs to reduce glucose levels. Herein, the first to provide the currently available potential benefits of chitosan in diabetes mellitus treatment focuses on chitosan-based nanocarriers for oral administration of various antidiabetic drugs nasal and subcutaneous passages. Moreover, chitosan is used to activate and deliver stem cells and differentiate them into cells similar to pancreatic beta cells as a new type of treatment for type one diabetes mellitus. The results of this review will be helpful in the development of promising treatments and better control of diabetes mellitus.

pH-sensitive chitosan-deoxycholic acid/alginate nanoparticles for oral insulin delivery

Oral absorption of peptides/proteins is usually compromised by various gastrointestinal tract barriers. To improve delivery efficiency, chitosan-conjugated deoxycholic acid (CS-DCA) coupled with sodium alginate (ALG) was prepared to load insulin into pH-sensitive nanoparticles. The insulin-loaded chitosan-deoxycholic acid/alginate nanoparticles (CDA NPs) were characterized by size (143.3 ± 10.8 nm), zeta potential (19.5 ± 1.6 mV), entrapment efficiency (61.14 ± 1.67%), and insulin drug loading (3.36 ± 0.09%). The CDA NPs exhibited pH-triggered release characteristics in vitro and protected the wrapped insulin from gastric degradation. Stability of the CDA NPs in enzyme-containing simulated gastrointestinal fluids suggested that the NPs could partially protect the wrapped insulin from enzymatic degradation. Additionally, CS-DCA-modified NPs promoted the permeability of Caco-2 cells and enhanced intracellular absorption of FITC-labeled insulin by 9.4 and 1.2-folds, when compared to insulin solution and unmodified NPs, respectively. The positively charged NPs increased intestinal villi adhesion and enhanced insulin absorption in the intestines of diabetic rat models. Furthermore, the hypoglycemic test showed that CDA NPs prolonged insulin release in vivo and exerted a remarkable hypoglycemic effect on diabetic rats with an oral bioavailability of 15%. In conclusion, CDA NPs is a potential oral insulin delivery system.

Functionalized Chitosan Nanomaterials: A Jammer for Quorum Sensing

The biggest challenge in the present-day healthcare scenario is the rapid emergence and spread of antimicrobial resistance due to the rampant use of antibiotics in daily therapeutics. Such drug resistance is associated with the enhancement of microbial virulence and the acquisition of the ability to evade the host’s immune response under the shelter of a biofilm. Quorum sensing (QS) is the mechanism by which the microbial colonies in a biofilm modulate and intercept communication without direct interaction. Hence, the eradication of biofilms through hindering this communication will lead to the successful management of drug resistance and may be a novel target for antimicrobial chemotherapy. Chitosan shows microbicidal activities by acting electrostatically with its positively charged amino groups, which interact with anionic moieties on microbial species, causing enhanced membrane permeability and eventual cell death. Therefore, nanoparticles (NPs) prepared with chitosan possess a positive surface charge and mucoadhesive properties that can adhere to microbial mucus membranes and release their drug load in a constant release manner. As the success in therapeutics depends on the targeted delivery of drugs, chitosan nanomaterial, which displays low toxicity, can be safely used for eradicating a biofilm through attenuating the quorum sensing (QS). Since the anti-biofilm potential of chitosan and its nano-derivatives are reported for various microorganisms, these can be used as attractive tools for combating chronic infections and for the preparation of functionalized nanomaterials for different medical devices, such as orthodontic appliances. This mini-review focuses on the mechanism of the downregulation of quorum sensing using functionalized chitosan nanomaterials and the future prospects of its applications.

Physicochemical features assessment of acemannan-based ternary blended films for biomedical purposes

The exploitation of natural origin macromolecules, as complex physical mixtures or drugs, increases in biomedical or tissue engineering (TE) solutions. Aloe Vera is a highly explored medicinal plant, from which the main polysaccharide is acemannan (ACE). The ACE combination with chitosan and alginate results in interactions that lead to mixed junction zones formation, predicting membrane functionality improvement. This work proposes the development and characterization of ACE-based blended films as a promising strategy to design a nature-derived bioactive platform. The results confirmed that stable complex polyelectrolyte structures were formed through different intermolecular interactions. The films present good dimensional stability, flexibility, an adequate swelling ability with mostly radial water uptake, and a sustainable ACE release to the medium. Positive biological performance of the ACE-based blended films with L929 cells also suggested that they can be applied in TE solutions, with the potential to act as bioactive topical platforms.

β-Cyclodextrin-containing chitosan-oligonucleotide nanoparticles improve insulin bioactivity, gut cellular permeation and glucose consumption

OBJECTIVES

The main objective of the present study was to develop a nanoparticulate drug delivery system that can protect insulin against harsh conditions in the gastrointestinal (GI) tract. The effects of the following employed techniques, including lyophilisation, cross-linking and nanoencapsulation, on the physicochemical properties of the formulation were investigated.

METHODS

We herein developed a nanocarrier via ionotropic gelation by using positively charged chitosan and negatively charged Dz13Scr. The lyophilised nanoparticles with optimal concentrations of tripolyphosphate (cross-linking agent) and β-cyclodextrin (stabilising agent) were characterised by using physical and cellular assays.

KEY FINDINGS

The addition of cryoprotectants (1% sucrose) in lyophilisation improved the stability of nanoparticles, enhanced the encapsulation efficiency, and ameliorated the pre-mature release of insulin at acidic pH. The developed lyophilised nanoparticles did not display any cytotoxic effects in C2C12 and HT-29 cells. Glucose consumption assays showed that the bioactivity of entrapped insulin was maintained post-incubation in the enzymatic medium.

CONCLUSIONS

Freeze-drying with appropriate cryoprotectant could conserve the physiochemical properties of the nanoparticles. The bioactivity of the entrapped insulin was maintained. The prepared nanoparticles could facilitate the permeation of insulin across the GI cell line.

Fabrication techniques for the preparation of orally administered insulin nanoparticles

The development of orally administered protein drugs is challenging due to their intrinsic unfavourable features, including large molecular size and poor chemical stability, both of which limit gastrointestinal (GI) absorption efficiency. Nanoparticles can overcome the GI barriers effectively and improve the oral bioavailability of proteins in the GI tract. They possess large surface area to volume ratio, and can facilitate the GI absorption of nanoparticles via the paracellular and transcellular routes. Nanoparticles can be prepared by various fabrication techniques that can encapsulate the fragile therapeutic proteins via hydrophobic bonding and electrostatic interaction. A desirable technique should involve minimal harsh conditions and encapsulate therapeutic proteins with preserved functionalities. The current review examines the characteristics of each preparation technique, and illustrates the examples of insulin-loaded nanoparticles that have been developed in each fabrication method. The following techniques, which include nanoprecipitation, hydrophobic conjugation, flash nanocomplexation, double emulsion, ionotropic gelation, and layer-by-layer adsorption, have been used to formulate ligand-modified nanoparticles for targeted delivery of insulin. Other techniques, including reduction, complex coacervation (polyelectrolyte complexation), hydrophobic ion pairing and emulsion solvent diffusion method, and sol-gel technology, were also discussed in the latter part of the review due to their extensive use in fabrication of insulin nanoparticles. This review also discusses the strategies that have been utilised during the formulation process to improve the stability and bioactivity of therapeutic proteins.

Optimization of Microbial Rennet Encapsulation in Alginate - Chitosan Nanoparticles

The milk-coagulating enzyme, rennet, is widely used in cheese making. Recently stabilization of rennet, especially in accelerated cheese ripening, has received considerable interest. As we know encapsulation is one of the enzyme immobilization methods, which could increase enzyme stability. In this study, the effects of alginate, chitosan and, CaCl₂ on rennet encapsulation were evaluated and optimized using RSM. Under the optimal conditions alginate, chitosan, and CaCl₂ were 0.04%, 0.1%, and 0.1% respectively. At the optimum point, encapsulation efficiency, particle size, and zeta potential were evaluated to be 61.8%, 323 nm, and 25 mV, respectively. The effect of temperature and pH on the enzyme activity was evaluated, and the results showed that encapsulated enzyme had higher activity at various pH and temperature in comparison with the free enzyme. Also, the enzyme release data in all pH values were fitted to Korsmeyer-Peppas model and the n exponent indicated that the release mechanism was Fickian. The electrostatic interactions between enzyme, alginate, and chitosan were confirmed by infrared spectroscopy. No statistical difference was found between the K_m and V_max of encapsulated and free enzymes.

Chitosan Nanoparticles-Insight into Properties, Functionalization and Applications in Drug Delivery and Theranostics

Nanotechnology-based development of drug delivery systems is an attractive area of research in formulation driven R&D laboratories that makes administration of new and complex drugs feasible. It plays a significant role in the design of novel dosage forms by attributing target specific drug delivery, controlled drug release, improved, patient friendly drug regimen and lower side effects. Polysaccharides, especially chitosan, occupy an important place and are widely used in nano drug delivery systems owing to their biocompatibility and biodegradability. This review focuses on chitosan nanoparticles and envisages to provide an insight into the chemistry, properties, drug release mechanisms, preparation techniques and the vast evolving landscape of diverse applications across disease categories leading to development of better therapeutics and superior clinical outcomes. It summarizes recent advancement in the development and utility of functionalized chitosan in anticancer therapeutics, cancer immunotherapy, theranostics and multistage delivery systems.

Response Surface Methodology for Statistical Optimization of Chitosan/Alginate Nanoparticles as a Vehicle for Recombinant Human Bone Morphogenetic Protein-2 Delivery

Purpose

In this study, chitosan/alginate nanoparticles are prospected as a carrier for controlled release of recombinant human bone morphogenetic protein-2 (rhBMP-2).

Materials and Methods

The rhBMP-2-loaded chitosan/alginate nanoparticles (Cs/Alg/B NPs) were prepared using the ionic gelation (IG) method. The current research was conducted to optimize the effective factors for entrapping rhBMP-2 in Cs/Alg NPs using response surface methodology (RSM) and the Box–Behnken design (BBD). The variables were the Cs/Alg molecular weight (Mw) ratios (1–3), pH (4.8–5.5), stirring rates (900–1300 rpm) and the responses included size, ζ-potential, polydispersity index (PDI), loading efficacy (LE), cumulative release (CR), and morphological degradation time (MDE). Then, the morphological properties of optimum formulation were studied for post-characterization. In the next step, the MTT assay for the optimized run was done for 24 and 48 hours.

Results

The results revealed that the optimum conditions for the mentioned variables were stirring rate=1100 rpm, pH=5.15, and Cs/Alg Mw ratio=1.75 based on numerical optimization. It was shown that the average particle size and loading efficacy at optimum conditions were 253 nm and 67%, respectively. Other responses were as follows: CR=66%, ζ-potential=+35mV, PDI=0.5, and MDT=7 days.

Conclusion

The results have suggested that the statistical optimization of rhBMP-2 offers the possibility of preparing Cs/Alg/B NPs with a favorable size, controlled release characteristics, and high loading efficiency. It is expected that the acquired optimum conditions will be useful for efficient rhBMP-2 delivery.

Development of polymeric nanoparticle gel prepared with the combination of ionic pre-gelation and polyelectrolyte complexation as a novel drug delivery of timolol maleate

OBJECTIVE

The purpose of this study was to overcome the undesired systemic absorption of skin topical administration of timolol maleate (TM) by developing the TM nanoparticle gel.

METHODS

TM-loaded nanoparticle (TMNP) was prepared by ionic pre-gelation of pectin (PCN) and calcium ions (CI) followed with polyelectrolyte complex using chitosan (CHI). TMNP was characterized by measuring the particle size, polydispersity index, zeta potential, encapsulation efficiency (EE), and the interaction between formula constituents. TM-loaded nanoparticle gel (TMNG) was prepared by using hydroxypropyl methylcellulose (HPMC) and was characterized by measuring the spreadability, pH, viscosity, and drug content. The drug release kinetics were analyzed using DDSolver add-in program.

RESULTS

TMNP possessed particle size of 175.2 ± 19.7 nm, polydispersity index of 0.528 ± 0.113, zeta potential of -10.86 ± 0.87 mV, and EE of 27.45 ± 2.34%. The electrostatic interactions between PCN, CI, and CHI that formed the nanoparticles were confirmed by the result of vibrational spectroscopy analysis. TMNG possessed spreadability of 60.80 ± 1.38 cm², pH of 5.154 ± 0.004, viscosity of 269.07 ± 5.83 cP, and drug content of 107.38 ± 1.77%. TM showed a sustained release manner within 24 h by following Korsmeyer-Peppas kinetical model with non-Fickian release mechanism.

CONCLUSION

The prepared nanoparticle gel can be an effective controlled release system of TM that administered topically on the skin surface.

Metal alginates for polyphenol delivery systems: Studies on crosslinking ions and easy-to-use patches for release of protective flavonoids in skin

Incorporation of bioactive natural compounds like polyphenols is an attractive approach for enhanced functionalities of biomaterials. In particular flavonoids have important pharmacological activities, and controlled release systems may be instrumental to realize the full potential of these phytochemicals. Alginate presents interesting attributes for dermal and other biomaterial applications, and studies were carried here to support the development of polyphenol-loaded alginate systems. Studies of capillary viscosity indicated that ionic medium is an effective strategy to modulate the polyelectrolyte effect and viscosity properties of alginates. On gelation, considerable differences were observed between alginate gels produced with Ca2+, Ba2+, Cu2+, Fe2+, Fe3+ and Zn2+ as crosslinkers, especially concerning shrinkage and morphological regularity. Stability assays with different polyphenols in the presence of alginate-gelling cations pointed to the choice of calcium, barium and zinc as safer crosslinkers. Alginate-based films loaded with epicatechin were prepared and the kinetics of release of the flavonoid investigated. The results with calcium, barium and zinc alginate matrices indicated that the release dynamics is dependent on film thicknesses, but also on the crosslinking metal used. On these grounds, an alginate-based system of convenient use was devised, so that flavonoids can be easily loaded at simple point-of-care conditions before dermal application. This epicatechin-loaded patch was tested on an ex-vivo skin model and demonstrated capacity to deliver therapeutically relevant concentrations on skin surface. Moreover, the flavonoid released was not modified and retained full antioxidant bioactivity. The alginate-based system proposed offers a multifunctional approach for flavonoid controllable delivery and protection of skin injured or under risk.

Evaluation of amygdalin-loaded alginate-chitosan nanoparticles as biocompatible drug delivery carriers for anticancerous efficacy

Amygdalin, despite possessing anticancerous properties, has been viewed as a controversial choice due to the presence of the cyanide group. Here, we synthesise and investigate the potential of alginate-chitosan nanoparticles (ACNPs) as drug delivery agents for amygdalin encapsulation and its delivery to cancer cells. Amygdalin loaded ACNPs were made with both anionic and cationic outer layer to further investigate charge dependency on drug delivery and cytotoxicity. ACNPs encapsulating amygdalin were monodisperse, colloidally stable with ~90% drug encapsulation efficiency and were entirely made from natural materials. The nanoparticles exhibited sustained drug release for a duration of 10 h and significant swelling rates in neutral and slightly acidic environments. The ACNPs successfully adhered to porcine mucin type II when assessed for its mucoadhesion and shown to transmigrate with an average velocity of 1.68 μm/s in uncoated channels, under biomimicked flow conditions. To investigate charge dependency on drug delivery and cytotoxicity, amygdalin loaded ACNPs were made with both anionic and cationic outer layer and assessed. ACNPs demonstrated greater yet sustained anti-cancerous effect on H1299 cell lines in a dose-dependent manner than free amygdalin suggesting greater cellular uptake of the former. In conclusion, biocompatible and biodegradable alginate-chitosan nanoparticles can be used as an effective drug delivery system for sustained and controlled amygdalin release with its improved cytotoxic effect on cancerous cells while protecting normal cells and tissues.

Bio-nanotechnological advancement of orally administered insulin nanoparticles: Comprehensive review of experimental design for physicochemical characterization

Therapeutic proteins are labile macromolecules that are prone to degradation during production, freeze-drying and storage. Recent studies showed that nanoparticles can enhance the stability and oral bioavailability of encapsulated proteins. Several conventional approaches (enzyme inhibitors, mucoadhesive polymers) and novel strategies (surface modification, ligand conjugation, flash nano-complexation, stimuli-responsive drug delivery systems) have been employed to improve the physiochemical properties of nanoparticles such as size, zeta potential, morphology, polydispersity index, drug release kinetics and cell-targeting capacity. However, clinical translation of protein-based nanoparticle is limited due to poor experimental design, protocol non-compliance and instrumentation set-up that do not reflect the physiological conditions, resulting in difficulties in mass production of nanoparticles and waste in research funding. In order to address the above concerns, we conducted a comprehensive review to examine the experimental designs and conditions for physical characterization of protein-based nanoparticles. Reliable and robust characterization is essential to verify the cellular interactions and therapeutic potential of protein-based nanoparticles. Importantly, there are a number of crucial factors, which include sample treatment, analytical method, dispersants, sampling grid, staining, quantification parameters, temperature, drug concentration and research materials, should be taken into careful consideration. Variations in research protocol and unreasonable conditions that are used in optimization of pharmaceutical formulations can have great impact in result interpretation. Last but not least, we reviewed all novel instrumentations and assays that are available to examine mucus diffusion capacity, stability and bioactivity of protein-based nanoparticles. These include circular dichroism, fourier transform infrared spectroscopy, X-ray diffractogram, UV spectroscopy, differential scanning calorimetry, fluorescence spectrum, Förster resonance energy transfer, NMR spectroscopy, Raman spectroscopy, cellular assays and animal models.

Multifunctional prosthetic polyester-based hybrid mesh for repairing of abdominal wall hernias and defects

This study involves the design, development and evaluation of a new multifunctional prosthetic mesh for treatment of abdominal wall defects without complications. The developed prosthetic mesh is a hybrid platform of both synthetic and natural materials with its backbone consisting of a synthetic commercial polyester fabric (CPF) to provide the required mechanical integrity. The CPF mesh was coated by a natural biodegradable, biocompatible and antimicrobial layer of chitosan (CS) incorporating phenytoin (PH)-loaded pluronic nanomicelles for healing promotion, and ciprofloxacin (CPX)-alginate polyelectrolyte complex-based microparticles as antibacterial agent. The prosthetic mesh was optimized and evaluated in-vitro and in-vivo. The optimum PH-loaded micelles had particle size of 95.42 nm, polydispersity index of 0.41, zeta potential of -18 and entrapment efficiency of 89.4%, while the optimum CPX microcomplexes had particle size of 1292.0 nm, polydispersity index of 0.8, zeta potential of -20.1, complexation efficiency of 81.1%, and minimum inhibitory concentration of 0.25 μg/ml and 0.125 μg/ml against Staphylococcus aureus and Pseudomonas aeruginosa, respectively. In-vivo study on abdominal wall defect dog model was conducted, followed by implantation of the proposed prosthetic meshes. The developed mesh depicted an efficient healing with excellent biocompatibility, and could be an ideal and feasible alternative prosthesis with many advantages such as low cost, inertness, mechanical stability, pliability, low infection rate, limited modification by body tissues, sterilizability, non-carcinogenicity, limited inflammatory reaction, hypoallergenic as well as minimal complications.

Biopolymeric pellets of polyvinyl alcohol and alginate for the encapsulation of Ib-M6 peptide and its antimicrobial activity against E. coli

The encapsulation of Ib-M6 antibacterial peptide in pellets of polyvinyl alcohol (PVA) and polyvinyl alcohol-alginate (PVA-Alg) matrices was carried out in order to explore its controlled release and activity against Escherichia coli K-12. The pellets were obtained by combined ice segregation induced self-assembly (ISISA) and freezing-thawing methods and their microstructure was studied by scanning electron microscopy. Bromothymol blue was used as a model compound to study the transport mechanisms and release from pellets. The results show that there is a significant effect of the total concentration of PVA precursor solutions, the mass ratio of PVA of different molecular weights and the addition of alginate on the microstructure and transport properties of pellets. The antibacterial activity of Ib-M6 against Escherichia coli K-12 was not affected by the encapsulation in PVA pellets. However, the release of Ib-M6 from PVA-Alg pellets was not possible, probably due to the electrostatic interaction of positively charged Ib-M6 and negatively alginate structure. Nonetheless, the controlled release of Ib-M6 from polymeric matrices can be fitting by modifying parameters such as the concentration and type of polymer precursors.

A journey through the emergence of nanomedicines with poly(alkylcyanoacrylate) based nanoparticles

Starting in the late 1970s, the pioneering work of Patrick Couvreur gave birth to the first biodegradable nanoparticles composed of a biodegradable synthetic polymer. These nanoparticles, made of poly(alkylcyanoacrylate) (PACA), were the first synthetic polymer-based nanoparticulate drug carriers undergoing a phase III clinical trial so far. Analyzing the journey from the birth of PACA nanoparticles to their clinical evaluation, this paper highlights their remarkable adaptability to bypass various drug delivery challenges found on the way. At present, PACA nanoparticles include a wide range of nanoparticles that can associate drugs of different chemical nature and can be administered in vivo by different routes. The most recent technologies giving the nanoparticles customised functions could also be implemented on this family of nanoparticles. Through different examples, this paper discusses the seminal role of the PACA nanoparticles' family in the development of nanomedicines.

Alginate Nanoparticles for Drug Delivery and Targeting

Nanotechnology refers to the control, manipulation, study and manufacture of structures and devices at the nanometer size range. The small size, customized surface, improved solubility and multi-functionality of nanoparticles will continue to create new biomedical applications, as nanoparticles allow to dominate stability, solubility and bioavailability, as well controlled release of drugs. The type of a nanoparticle, and its related chemical, physical and morphological properties influence its interaction with living cells, as well as determine the route of clearance and possible toxic effects. This field requires cross-disciplinary research and gives opportunities to design and develop multifunctional devices, which allow the diagnosis and treatment of devastating diseases. Over the past few decades, biodegradable polymers have been studied for the fabrication of drug delivery systems. There was extensive development of biodegradable polymeric nanoparticles for drug delivery and tissue engineering, in view of their applications in controlling the release of drugs, stabilizing labile molecules from degradation and site-specific drug targeting. The primary aim is to reduce dosing frequency and prolong the therapeutic outcomes. For this purpose, inert excipients should be selected, being biopolymers, e.g. sodium alginate, commonly used in controlled drug delivery. Nanoparticles composed of alginate (known as anionic polysaccharide widely distributed in the cell walls of brown algae which, when in contact with water, forms a viscous gum) have emerged as one of the most extensively characterized biomaterials used for drug delivery and targeting a set of administration routes. Their advantages include not only the versatile physicochemical properties, which allow chemical modifications for site-specific targeting but also their biocompatibility and biodegradation profiles, as well as mucoadhesiveness. Furthermore, mechanical strength, gelation, and cell affinity can be modulated by combining alginate nanoparticles with other polymers, surface tailoring using specific targeting moieties and by chemical or physical cross-linking. However, for every physicochemical modification in the macromolecule/ nanoparticles, a new toxicological profile may be obtained. In this paper, the different aspects related to the use of alginate nanoparticles for drug delivery and targeting have been revised, as well as how their toxicological profile will determine the therapeutic outcome of the drug delivery system.

Effects of Calcium Alginate Submicroparticles on Seed Germination and Seedling Growth of Wheat (Triticum aestivum L.)

Calcium alginate (CaAlg) submicroparticles have a potential application in agricultural delivery systems. This study investigated the effects of CaAlg submicroparticles on seed germination and seedling growth of wheat. CaAlg submicroparticles with a Z-average diameter of around 250.4 nm and a measured zeta potential value of about −25.4 mV were prepared and characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS). After this, the effects of the concentration of CaAlg submicroparticles (10–500 μg/mL) on germination percentage, seedling length, the number of adventitious roots, chlorophyll content and soluble protein content were evaluated. The results demonstrated a significant increase in the level of germination percentage (9.0%), seedling index (50.3%), adventitious roots (27.5%), seedling length (17.0%), chlorophyll (8.7%) and soluble protein contents (4.5%) at a concentration of 100 μg/mL. However, an inhibitory effect was observed at a concentration of 500 μg/mL. The SEM examination showed that CaAlg submicroparticles could be successfully adsorbed onto the surface of the wheat seed. Further studies proved that CaAlg submicroparticles at a concentration of 100 μg/mL promoted the expression of indole-3-acetic acid (IAA)-related genes (YUCCA9, AUX1, ARF and UGT) in wheat, which resulted in an increase of 69% and 21% in IAA concentration in wheat roots and shoots, respectively.

Targeted folate-conjugated pluronic P85/poly(lactide-co-glycolide) polymersome for the oral delivery of insulin

Aim: To explore the better efficacy of targeted folic acid (FA)-Pluronic 85-poly(lactide-co-glycolide) (FA–P85–PLGA) polymersome in oral insulin delivery. Materials & methods: The cytotoxicity of the polymers, in vitro qualitative and quantitative cellular uptake and the internalization mechanism of insulin-loaded FA–P85–PLGA and PLGA–P85–PLGA polymersomes were studied with the human colon adenocarcinoma cells (Caco-2 cells). Their pharmacodynamics and pharmacokinetics properties were also studied with diabetic rats. Results & conclusion: Polymersomes have shown good biocompatibility. Polymersomes are mainly localized within the cytoplasm of Caco-2 cells from fluorescence microscopy images. FA–P85–PLGA exhibited higher cellular uptake than PLGA–P85–PLGA polymersomes and free fluorescein isothiocyanate-labeled insulin (FITC–insulin) did. The uptake process of targeted polymersomes included clathrin- and caveolae-mediated endocytosis, macropinocytosis and the folate receptor-mediated endocytosis. Insulin-loaded FA–P85–PLGA showed better hypoglycemic effects than insulin-loaded PLGA–P85–PLGA.

Development of chitosan coated calcium-alginate nanocapsules for oral delivery of liraglutide to diabetic patients

Chitosan coated calcium-alginate nanocapsules were developed for oral sustained delivery of liraglutide. The effect of coating components including sodium alginate, calcium chloride, and chitosan concentrations on the particle size was studied based on response surface methodology. The beads were characterized by dynamic light scattering, scanning and transmission electron microscopy as well as Fourier transform infrared spectroscopy. It was shown that the diameter of the formed beads was most dependent on the encapsulation technique and alginate concentration. SEM revealed spherical and smooth particles of up to 100 nm diameter for the optimum composition of alginate 0.5%, chitosan 0.5% and calcium chloride 0.5% in the volume ratio of 3:1:1. The resulting bead formulation had a loading efficiency of 92.5% and loading capacity of 54.16%. The nanocapsules exhibited stability of 92.4% and 72.3% over freeze drying and subsequent 60 days storage at 4 °C, respectively. In-vitro release studies in simulated gastrointestinal conditions were carried out in a sequential technique and the amount of drug release was found to be 59.1% after 6 h. The results of this study demonstrated that chitosan coated calcium-alginate nanocapsules hold promise as a potential natural biodegradable polymer-based oral carrier of liraglutide for better management of diabetes.