Objectives: The objective of this study was to utilize a chitosan-based nanoparticle system as the delivery carrier for glutamic acid, a model for encapsulated biomolecules to visualize the in vitro release and accumulation of the encapsulated glutamic acid from chitosan nanoparticle (CNP) systems.
Methods: CNP was synthesized via ionic gelation routes utilizing tripolyphosphate (TPP) as a cross-linker. In order to track glutamic acid release, the glutamic acid was fluorescently-labeled with fluorescein isothiocyanate prior encapsulation into CNP.
Results: Light Scattering data concluded the successful formation of small-sized and mono-dispersed CNP at a specific volume ratio of chitosan to TPP. Encapsulation of glutamic acid as a model cargo into CNP led to an increase in particle size to >100 nm. The synthesized CNP exhibited spherical shape under Electron Microscopy. The formation of CNP was reflected by the reduction in free amine groups of chitosan following ionic crosslinking reactions. The encapsulation of glutamic acid was further confirmed by Fourier Transform Infrared (FTIR) analysis. Cell viability assay showed 70% cell viability at the maximum concentration of 0.5 mg/mL CS and 0.7 mg/mL TPP used, indicating the low inherent toxicity property of this system. In vitro release study using fluorescently-tagged glutamic acids demonstrated the release and accumulation of the encapsulated glutamic acids at 6 hours post treatment. A significant accumulation was observed at 24 hours and 48 hours later. Flow cytometry data demonstrated a gradual increase in intracellular fluorescence signal from 30 minutes to 48 hours post treatment with fluorescently-labeled glutamic acids encapsulated CNP.
Conclusion: These results therefore suggested the potential of CNP system towards enhancing the intracellular delivery and release of the encapsulated glutamic acids. This CNP system thus may serves as a potential candidate vector capable to improve the therapeutic efficacy for drugs and biomolecules in medical as well as pharmaceutical applications through the enhanced intracellular release and accumulation of the encapsulated cargo.
OBJECTIVE: To date, numerous conventional wound dressings are employed for the management of DFUs but there is a lack of absolute and versatile choice. The current review was therefore aimed to summarize and critically discuss the available evidences related to pharmaceutical and therapeutic viability of polymer-based dressings for the treatment of DFUs.
RESULTS: A versatile range of naturally-originated polymers including chitosan (CS), hyaluronic acid (HA), cellulose, alginate, dextran, collagen, gelatin, elastin, fibrin and silk fibroin have been utilized for the treatment of DFUs. These polymers have been used in the form of hydrogels, films, hydrocolloids, foams, membranes, scaffolds, microparticles, and nanoparticles. Moreover, the wound healing viability and clinical applicability of various mutually modified, semi-synthetic or synthetic polymers have also been critically discussed.
CONCLUSION: In summary, this review enlightens the most recent developments in polymer-based wound dressings with special emphasis on advanced polymeric biomaterials, innovative therapeutic strategies and delivery approaches for the treatment of DFUs.
Methods: The TQ-PLGA NPs were prepared and characterized for size, zeta potential, encapsulation efficiency, and release profile.
Results: The particle size was 147.2 nm, with 22.1 positive zeta potential and 96.8% encapsulation efficiency. The NPs released 45.6% of the encapsulated TQ within 3 h followed by characteristic sustained release over 7 days with a total of 69.7% cumulative release. TQ-PLGA NPs were taken up effectively by the cells in a time-dependent manner up to 24 h. Higher cell toxicity was determined within the first 24 h in melanoma cells due to the rapid release of TQ from the NPs and its low stability in the cell culture media.
Conclusion: TQ-PLGA NPs is a potential anticancer agent taking advantage of the sustained release and tailored size that allows accumulation in the cancer tissue by the enhanced permeability and retention effect. However, stability problems of the active ingredient were address in this study and requires further investigation.