Synthesis of Chitosan-Based Hydrogels as a Novel Drug Release Device for Wound Healing

The development of the porous, biocompatible and biodegradable hydrogels has been gaining much attention for wound dressing applications. The hydrogels prepared using freeze-thawing method present important properties of high biocompatibility and nontoxicity. The hydrogels that are able to release drugs for prolonged time are widely used biomaterials for wound healing. In this study chitosan CS -based poly-ε-caprolactone PCL hydrogels were prepared using poly vinyl alcohol PVA , poly ethylene glycol PEG and poly vinyl pyrrolidone PVP . PVA-CS-PCL hydrogels only could remain stable at room temperature after synthesis. The properties of the hydrogels were determined with SEM, FTIR, swelling tests and degradation tests. The drugs of ceftazidime CZ as an antibiotic and ketoprofen KP as an analgesic were loaded onto the hydrogels and the loaded hydrogels were used for the drug release studies at pH 5.5 and pH 7.4. All these results suggest that the developed PVA-CS-PCL hydrogels offer significant potential as a wound dressing material

Potential evaluation of PVA-based hydrogels for biomedical applications

P oly vinyl alcohol PVA -based hydrogels prepared using freeze/thawing treatment have become increasingly important biomaterials for biomedical applications having great properties such as biocompatibility, biodegradability and high water absorbency. In this study, PVA-based physically cross-linked hydrogels were prepared with and without the presence of poly ethylene glycol PEG freezing at -16 °C for 16 h and thawing at room temperature for 8 h. The focus of this work was to address the effect of the addition of PEG Mw: 2000 or 5000 and the effect of the number of freezing/thawing cycles on swelling behaviour. The Scanning Electron Microscopy SEM measurements demonstrated the morphological characteristics of PVA-based hydrogels indicating the formation of the macroporosity fabricated during freeze/thawing process. From the swelling tests undertaken it w as apparent that all the hydrogels exhibited unique swelling characteristics having high swelling degree at all pH values such as pH 2.1, 5.5 and 7.4 representing the pH values of stomach, blood and dermis. Thus, the hydrogels synthesized in this study present important potential for biomedical application

Assessment of Centella Asiatica Extract Containing Dual-crosslinked Gel-MA/Pec Hydrogels as Wound Dressing

In the present work, 3D-printed wound dressings containing different amounts of Centella Asiatica extract were synthesized via dual-crosslinking method. Methacrylic anhydride modified gelatin (Gel-MA) and pectin (Pec) were chosen as the base material for dressings. A dual crosslinked network was formed with Gel-MA photo-crosslinking using Irgacure 2959 and Pectin (Pec) psychical-crosslinking using Ca++ ions. Meanwhile, the developed dual-crosslinked hydrogel dressings were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and mechanical, swelling, in vitro degradation as well as ex vivo bioadhesion tests. It has been observed that the preapred dressings provide good bioadhesion on the chicken skin. Moreover, MTT assay revealed cell viability of Gel-MA/Pec hydrogel dressings containing Centella Asiatica extract. The results presented the dressings as a promising biomaterial to be used for wound healing purposes, which should be further investigated in future

Synthesis and Characterization of Poly (VCL-HEA-IA) Terpolymer for Drug Release Applications

In the present work, poly(VCL-HEA-IA) terpolymeric hydrogels were synthesized by free radical polymerization of N-vinylcaprolactam (VCL), 2-hydroxethyl acrylate (HEA), and itaconic acid (IA) monomers using N,N'-methylene bisacrylamide (NMBA) as crosslinker and 2,2'-azobis (2-methylpropanimidamide) dihydrochloride (AMPA) as initiator. The swelling properties of these hydrogels were investigated at different pH and temperatures. Drug loading and release properties were also determined using Rhodamine B (RhB) as a model drug by UV-vis spectrophotometer at 554 nm. Drug loading capacities of hydrogels increased with increasing the ratio of hydrophilic monomer in hydrogel structure. Ionized hydrophilic groups of IA and HEA monomers increase the probability of interaction between the hydrophilic groups and the model drug in the phosphate buffer solution. To investigate the effect of different pH values on drug release, it was studied at pH 2.1, pH 5.5 and pH 7.2 in the buffer solutions at 37 degrees C. The model drug was released in proportion to 50% within the first 8 h at different pH values. At pH 7.2, the model drug was more quickly released due to the ionization of hydrophilic groups of IA and HEA. In addition, the surface morphology of drug loaded hydrogels was examined by scanning electron microscopy (SEM) which revealed uniform distribution of the drug in the hydrogel structure. It is concluded that, model drug loading capacity and release amount changed with composition of hydrogels. Maximum drug release and loading capacities were observed for hydrogel which contain the highest amount of HEA and IA monomers. Poly(VCL-HEA-IA)terpolymeric hydrogels are suitable for drug delivery applications