Aloe vera and ofloxacin incorporated chitosan hydrogels show antibacterial activity, stimulate angiogenesis and accelerate wound healing in full thickness rat model.

Burns are potentially fatal and physically debilitating injuries, causing psychological and physical scars and result in chronic disabilities. A well vascularized wound bed is required to achieve complete and scar free wound closure. For many centuries, a variety of herbal plants have been used for wound healing, among these aloe vera (AV) has been found to be very effective in wound healing. Secondly, the main reason for delayed wound healing is bacterial infections. Ofloxacin (OX) has been reported as an active antibacterial drug for topical infections and it is effective against both positive and negative bacterial strains. In current research three different concentrations of OX (0.5, 2.5, and 5 mg) were loaded into chitosan (CS)/AV based hydrogels prepared by freeze gelation. The surface morphology of prepared CS/AV based OX loaded hydrogels were evaluated by scanning electron microscopy (SEM). In drug release analysis, 0.5 mg OX loaded hydrogel showed a sustained drug release behavior over 3 days period. An effective dose dependent antibacterial activity was exhibited by OX loaded hydrogels. Alamar Blue cells viability assay revealed that 0.5 mg OX hydrogel (CA 0.5 OX) showed comparatively better 3 T3 fibroblast cells proliferation as compared to CA 2.5 OX (2.5 mg OX) and CA 5 OX hydrogel (5 mg OX). Moreover, all OX loaded hydrogels showed good angiogenic activity in CAM bioassay while higher angiogenic potential was observed from CA 0.5 OX containing comparatively lower concentration of OX. These OX incorporated CS/AV based hydrogels are promising wound dressings for future clinical use.

A study of the comparative effect of cerium oxide and cerium peroxide on stimulation of angiogenesis: Design and synthesis of pro-angiogenic chitosan/collagen hydrogels.

Poor angiogenesis at injury site is a major problem in chronic wounds, which could lead to limbs amputation in adverse cases. To overcome this issue, several efforts have made in literature and by our group as well to develop pro-angiogenic agents. For this purpose, metal oxides due to their oxidative potential have been studied and found very attractive agents. Cerium oxides are proven to be non-toxic and their biological studies have already proved their importance in preventing chronic inflammation, and neurological diseases among several others by modulating the intracellular reactive oxygen species. In current study, we report the synthesis and neovascularization activity of cerium oxide and cerium peroxide nanoparticles when loaded into chitosan and collagen hydrogel. The hydrogels were characterized by FTIR, SEM and XRD. The pro-angiogenic behavior of these hydrogels was studied by in-vivo CAM assay. It was found that cerium peroxide loaded material showed significantly increase in angiogenesis as compared to cerium oxide loaded materials. It was demonstrated that cerium peroxide hydrogels enhanced the angiogenic capability in CAM assay as compared to cerium oxide and hence holds good potential for chronic ulcer and burn wounds healing.

Thyroxine impregnated chitosan-based dressings stimulate angiogenesis and support fast wounds healing in rats: Potential clinical candidates.

This research paper demonstrates efficacy of chitosan and thyroxine loaded chitosan (CS) dressings for their angiogenic and wound healing potential. The dressings were prepared by freeze gelation method. Thyroxine was loaded by physical adsorption into chitosan membranes. The porosity was analyzed by scanning electron microscopy (SEM) and chemical structures were investigated by Fourier transform infra-red spectroscopy (FTIR). Cell culture studies showed materials were non-toxic and chorioallantoic membranes assay (CAM) confirmed that the thyroxine loaded chitosan stimulated angiogenesis much higher than simple chitosan dressings. In addition, thyroxine loaded dressings showed excellent wound healing potential when tested on full thickness rats wounds. A good epithelialization was obtained along with robust wound closure. Overall, as compared to chitosan, thyroxine containing membranes showed high level of angiogenesis and fast wound healing.

Amino acids loaded chitosan/collagen based new membranes stimulate angiogenesis in chorioallantoic membrane assay.

Chitosan/collagen-based hydrogels were studied for their promising role in skin tissue engineering applications due to their unique biocompatibility and biodegradation properties. Amino acids are not only the mean of protein building units but also support endothelial cells proliferation and trigger angiogenesis during wound healing. The purpose of this study was to prepare amino acid based pro-angiogenic materials. Three structurally closed amino acids (AA) (arginine, alanine and phenylalanine) were loaded into chitosan/collagen hydrogels (ACC hydrogels) to study their effect on angiogenesis. In this study the ACC hydrogels were prepared through freeze drying procedure and their angiogenic potential was studied by chorioallantoic membrane assay (CAM assay). FTIR analysis was performed to confirm that there was no chemical change took place in polymeric materials during synthesis procedures. Results revealed that, arginine-loaded hydrogels were the most porous, with more interconnected pores and also the maximum growth of blood vessels were found around and inside the arginine loaded scaffold. The qualitative analysis for blood vessels showed the significant difference between control, chitosan/collagen alanine loaded hydrogel (CH-Ala), chitosan/collagen phenylalanine loaded hydrogel (CH-Phe) and chitosan/collagen arginine loaded hydrogel (CH-Arg) materials. Among these studied materials the CH-Arg was found more capable for angiogenesis.