Size-dependent bioactivity of electrosprayed core-shell chitosan-alginate particles for protein delivery

A review of chitosan role in milk bioactive-based drug delivery, smart packaging and biosensors: Recent advances and developments

Chitosan, a versatile biopolymer derived from chitin, is increasingly recognized in the milk industry for its multifunctional applications in drug delivery, smart packaging, and biosensor development. This review provides a comprehensive analysis of recent advances in chitosan production techniques. These include chemical, biological, and novel methods such as deep eutectic solvents (DES), microwave-assisted approaches, and laser-assisted processes. Surface modification strategies to enhance its functional properties are also discussed. The review highlights the development of various chitosan-based nanocarriers, including nanoparticles, nanofibers, nanogels, and nanocomposites. It emphasizes their stability when combined with milk bioactive ingredients like lipids, peptides, lactose, and minerals. The gastrointestinal fate and safety of chitosan nanoparticles are critically evaluated, showcasing their potential for safe consumption in dairy-related applications. In drug delivery systems, chitosan exhibits excellent compatibility with milk-derived carbohydrates, proteins, and minerals, enabling the development of innovative drug delivery platforms. Additionally, its incorporation into smart packaging materials enhances the shelf-life and quality of dairy products. Chitosan-based biosensors offer precise contaminant detection in the milk industry by enabling precise detection of contaminants such as Bisphenol A, melamine, bacteria, drugs, antibiotics, toxins, heavy metals, and allergens, thus ensuring food safety and quality. Emerging trends, including the integration of artificial intelligence, advanced gene editing, and multifunctional chitosan, are discussed, offering insights into future personalized delivery systems and merging food and drug technologies. The review concludes by highlighting gaps in current research and offering recommendations for future exploration. These suggestions aim to optimize chitosan's unique properties to address key challenges in the milk industry. This article serves as a valuable resource for researchers, industry professionals, and policymakers aiming to innovate within the dairy sector using chitosan-based technologies.

Development of a Thermoresponsive Core-Shell Hydrogel for Sequential Delivery of Antibiotics and Growth Factors in Regenerative Endodontics

BACKGROUND

Regenerative endodontics requires an innovative delivery system to release antibiotics/growth factors in a sequential trend. This study focuses on developing/characterizing a thermoresponsive core-shell hydrogel designed for targeted drug delivery in endodontics.

METHODS

The core-shell chitosan-alginate microparticles were prepared by electrospraying to deliver bone morphogenic protein-2 for 14 days and transforming growth factor-beta 1 (TGF-β1) for 7-14 days. Methylcellulose (MC) and gelatin were utilized to create the core-shell hydrogel to load a modified triple antibiotic combination (penicillin G/metronidazole/ciprofloxacin (PMC)) and growth factor-loaded microparticles in the shell and the core compartments, respectively. Morphological assessment, core-shell structural analysis, FTIR analysis, rheological analysis, swelling, and degradation rate studies were conducted for characterization. The viability of dental pulp stem cells (DPSCs) upon antibiotic exposure, antibacterial activity, and release studies of PMC and growth factors were investigated. Cellular studies (cell viability, alkaline phosphatase (ALP) activity, osteo/odontoblast gene expression (using Reverse transcription-polymerase chain reaction (RT-PCR)) and in vivo studies (inflammatory response and differentiation potential of the developed hydrogel by subcutaneous implantation in rats via histological examination) were assessed.

RESULTS

The hydrogel showed a porous microstructure with interconnected pores. Core-shell structure analysis confirmed the successful extrusion of the MC hydrogel to the surface. FTIR analysis revealed interactions between MC and gelatin. Rheological analysis indicated time-dependent gel formation, supporting thermosensitivity at 37 °C. Swelling occurred rapidly, and degradation reached 62.42% on day 45. Further, antibiotics exhibited no cytotoxicity on DPSCs. Sequential release of antibiotics and growth factors was observed for up to 5 and 14 d, respectively. The hydrogel showed antibacterial activity. DPSCs exhibited increased proliferation, ALP activity, and odontoblast gene expression. In vivo studies showed that the biocompatible drug-loaded hydrogel exhibited more mineralization than the control.

CONCLUSIONS

The developed core-shell hydrogel containing PMC and growth factor-loaded core-shell microparticles provided a versatile and biocompatible platform for sequential drug delivery in regenerative endodontics. The system demonstrates promising characteristics for dentin regeneration, making it a potential candidate for clinical applications.

Dual-Responsive Alginate/PNIPAM Microspheres Fabricated by Microemulsion-Based Electrospray

Smart materials for drug delivery are designed to offer a precise and controlled release of therapeutic agents. By responding to specific physiological stimuli, such as changes in temperature and pH, these materials improve treatment efficacy and minimize side effects, paving the way for personalized therapeutic solutions. In this study, we present the fabrication of dual-responsive alginate/poly(N-isopropylacrylamide) (PNIPAM) microspheres, having the ability to respond to both pH and temperature variations and embedding the lipophilic bioactive compound Ozoile. Ozoile® Stable Ozonides is obtained from extra virgin olive oil and acts as an inducer, interacting with major biological pathways by means of modulating the systemic redox balance. The dual-responsive microspheres are prepared by electrospray technique without the use of organic solvents. PNIPAM is synthesized by radical polymerization using the APS/TEMED redox initiators. The microspheres are further optimized with a chitosan coating to enhance their stability and modulate the degradation kinetics of the gel matrix. A comprehensive morphological analysis, Fourier transform infrared (FTIR) spectroscopy, and degradation assays are conducted to confirm the structural stability and pH-responsive behavior of the hydrogel microspheres. A study of the volume phase transition temperature (VPTT) by differential scanning calorimetry (DSC) is used to assess the microsphere thermal response. This research introduces a promising methodology for the development of targeted drug delivery systems, which are particularly useful in the context of oxidative stress modulation and inflammation management.

Effect of simultaneous and sequential use of TGF-β1 and TGF-β3 with FGF-2 on teno/ligamentogenic differentiation of periodontal ligament stem cells

OBJECTIVE

The periodontal ligament is a crucial part of the periodontium, and its regeneration is challenging. This study compares the effect of simultaneous and sequential use of FGF-2 and TGF-β1 with FGF-2 and TGF-β3 on the periodontal ligament stem cells (PDLSCs) teno/ligamentogenic differentiation.

DESIGN

This study comprises ten different groups. A control group with only PDLSCs; FGF-2 group containing PDLSCs with a medium culture supplemented with FGF-2 (50 ng/mL). In other experimental groups, different concentrations (5 ng/mL or 10 ng/mL) of TGF-β1&-β3 simultaneously or sequentially were combined with FGF-2 on the cultured PDLSCs. TGF-β was added to the medium after day 3 in the sequential groups. Methyl Thiazolyl Tetrazolium (MTT) assay on days 3, 5, and 7 and Quantitative Real-time Polymerase Chain Reaction (RT-qPCR) analysis after day 7 were conducted to investigate PLAP1, SCX, and COL3A1, RUNX2 genes. All experiments were conducted in a triplicate. The One-way and Two-way ANOVA with Tukey post hoc were utilized to analyze the results of the MTT and RT-qPCR tests, respectively. A p-value less than 0.05 is considered significant.

RESULTS

The proliferation of cells on days 3, 5, and 7 was not significantly different among different experimental groups (P > 0.05). A higher expression of the PLAP1, SCX, and COL3A1 have been seen in groups with sequential use of growth factors; among these groups, the group using 5 ng/mL of TGF-β3 led other groups with the most amount of significant upregulation in PLAP1(17.69 ± 1.11 fold; P < 0.0001), SCX (5.71 ± 0.38 fold; P < 0.0001), and COL1A3 (6.35 ± 0.39 fold; P < 0.0001) expression, compared to the control group. The expression of the RUNX2 decreased in all groups compared to the control group; this reduction was more in groups with sequential use of growth factors.

CONCLUSION

The sequential use of growth factors can be more effective than simultaneous use in teno/ligamentogenic differentiation of PDLSCs. Moreover, treatment with 5 ng/mL TGF-β3 after FGF-2 was more effective than TGF-β1.

pNIPAm-Based pH and Thermoresponsive Copolymer Hydrogel for Hydrophobic and Hydrophilic Drug Delivery

The regulated and targeted administration of hydrophobic and hydrophilic drugs is both promising and challenging in the field of drug delivery. Developing a hydrogel which is responsive to dual stimuli is considered a promising and exciting research area of study. In this work, melamine functionalized poly-N-isopropyl acrylamide-co-glycidyl methacrylate copolymer has been developed by copolymerizing glycidyl methacrylate (GMA) monomer with N-isopropyl acrylamide (NIPAm) and further functionalized with melamine units (pNIPAm-co-pGMA-Mela). The prepared pNIPAm-co-pGMA-Mela copolymer hydrogel was characterized using various characterization techniques, including 1H NMR, FTIR, SEM, zeta potential, and particle size analysis. A hydrophobic drug (ibuprofen, Ibu) and hydrophilic drug (5-fluorouracil, 5-Fu) were selected as model drugs. Dual pH and temperature stimuli-responsive drug release behavior of the pNIPAm-co-pGMA-Mela hydrogel was evaluated under different pH (pH 7.4 and 4.0) and temperature (25 °C, 37 °C, and 45 °C) conditions. Furthermore, the in vitro biocompatibility of the developed pNIPAm-co-pGMA-Mela copolymer hydrogel was determined on MDA-MB-231 cells. The pH and temperature-responsive drug delivery study results reveal that the pNIPAm-co-pGMA-Mela hydrogel system is responsive to both pH and temperature stimuli and exhibits about ~100% of Ibu and 5-Fu, respectively, released at pH 4.0/45 °C. Moreover, the MTT assay and hemocompatibility analysis results proved that the pNIPAm-co-pGMA-Mela hydrogel system is biocompatible and hemocompatible, suggesting that that it could be used for drug delivery applications. The experimental results suggest that the proposed pNIPAm-co-pGMA-Mela hydrogel system is responsive to dual pH and temperature stimuli, and could be a promising drug carrier system for both hydrophilic and hydrophobic drug delivery applications.

Modulation the Synergistic Effect of Chitosan-Sodium Alginate Nanoparticles with Ca2+: Enhancing the Stability of Pickering Emulsion on D-Limonene

Pickering emulsions (PEs) have been regarded as an effective approach to sustaining and preserving the bioactivities of essential oils. The aim of this research is to prepare a PE stabilized by chitosan/alginate nanoparticles (CS-SA NPs) for the encapsulation and stabilization of D-limonene. In this work, the influence of calcium ions (Ca2+) on the morphology and interaction of nanoparticles was studied, and then the preparation technology of CS-SA/Ca2+ NPs was optimized. The results showed that the presence of Ca2+ reduced the size of the nanoparticles and made them assume a spherical structure. In addition, under the conditions of 0.2 mg/mL CaCl2, 0.6 mg/mL SA, and 0.4 mg/mL CS, the CS-SA/Ca2+ NPs had the smallest size (274 ± 2.51 nm) and high stability (-49 ± 0.69 mV). Secondly, the PE was prepared by emulsifying D-limonene with CS-SA/Ca2+ NPs, and the NP concentrations and homogenization speeds were optimized. The results showed that the small droplet size PE could be prepared with 2 mg/mL NP and a homogenization speed of 20,000 r/min, and it had excellent antibacterial and antioxidant activities. Most importantly, the emulsion showed higher activity, higher resistance to ultraviolet (UV) and a higher temperature than free D-limonene. This research provides a feasible solution for the encapsulation, protection and delivery of essential oils.

Graphene oxide reinforced chitosan/polyvinyl alcohol antibacterial coatings on stainless steel surfaces exhibit superior bioactivity without human cell cytotoxicity

The study proposes an alternative therapeutics to diminish bacterial attachment in biomedical implants by modifying their surface with passive coatings. A uniform, thin-film of chitosan/polyvinyl alcohol/graphene oxide (CS/PVA/GO) was coated on 316 L stainless steel (SS) surface through spread casting followed by solvent evaporation. The abundant anchoring sites available at macromolecular interfaces of chitosan/PVA matrix facilitated a smooth, dense loading of GO. The effect of GO content on physicochemical features, antibacterial potential, and biocompatibility of coatings was thoroughly studied. The hybrid films displayed good adhesion behavior, and UV-protection ability with desired mechanical and thermal stability when coated on SS surface. Coatings manifested a 1.5-1.7 fold rise in antibacterial efficacy against Staphylococcus epidermidis and Staphylococcus aureus and exhibited a permanent biocidal response after 6 h of contact-active behaviour. We investigated a 3-fold generation of reactive oxygen species as the predominant antibacterial mechanism, which diminishes bacterial integrity by inducing protein leakage (8.5-9 fold higher) and suppressing respiratory chain activity as two secondary mechanisms. All coatings with varying GO content appeared non-haemolytic (<2%) with ultra-low cytotoxicity (<29.08%) against human hepatocellular carcinoma (HepG2) and peripheral blood mononuclear cells. The degradation rate of coatings in simulated body fluid exhibited a higher stability, indicated by a lower weight loss (69-78%) and a decrease in pH values as the GO content in coatings increased from 0.05 to 0.15 wt%. Such anti-infective coating is a step forward in inhibiting bacterial colonization on SS surfaces to extend its lifespan.