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Though chitosan hydrogels have shown potential for numerous tissue regeneration applications, its insolubility above pH 6.0 have greatly limited applicability in encapsulation of live cells and pH sensitive bioactive agents. In this report an approach to overcome this limitation was tested with phosphorylated derivative of chitosan, N-methylene phosphonic chitosan (NMPC). NMPC is also known to possess efficacious gene delivery, biomineralization, and osteoinduction properties. NMPC hydrogels were synthesized by cross-linking NMPC with either glutaraldehyde (NMPC-GLU) or genipin (NMPC-GEN). An increase in pH from 3.0 to 6.8 reduced gelation time with both the agents, with the reduction more pronounced in NMPC-GLU. The results correlated with the reaction mechanisms of both agents with NMPC. Further NMPC-GEN gels demonstrated higher elastic modulus and compressive strength values. Cell culture studies showed higher cell proliferation on NMPC-GEN compared to NMPC-GLU. [Supplementary materials are available for this article. Go to the Publisher's online edition ofSoft Materialsfor the following free supplemental resource(s): Supporting information of Pallab Datta et al.] [ABSTRACT FROM AUTHOR]

Hydrogels have evolved over the last decade as materials of choice in varied biomedical applications. This is associated with the inherent biocompatible nature of the hydrogels. The modulation of the properties of the hydrogels is easily possible due to the availability of polymers of varied chemistry and physical properties. This review discusses the pharmaceutical aspects of the controlled release of bioactive agents from hydrogel-based formulations. [ABSTRACT FROM PUBLISHER]

In recent years, chitosan, a biocompatible natural polymer, having a cellulosic backbone has gained importance in various biomedical applications like wound healing, tissue engineering, surface modifications of implantable devices, and drug delivery. This may be attributed to the versatile chemistry of the polymer. Various chitosan-mediated delivery systems have been developed to improve the bioavailability of drug(s) and be categorized either as nanoparticulate, microparticulate, or macro delivery systems. All these delivery systems have their own advantages and limitation as a delivery vehicle. This review gives an overview of the chitosan-based drug delivery systems. [ABSTRACT FROM AUTHOR]

Emulsion gels are now emerging as a new class of biomaterials for controlled-release applications. Novel food-grade emulsion gels consisting of indomethacin-loaded vegetable oil droplets dispersed within genipin-cross-linked gelatin-based hydrogels were characterized for their physical and drug-release properties. Varying the weight ratio of the aqueous and oil phases between 5:1 and 5:5 was used to modulate construct swelling and drug release. The dispersed oil droplets generally became larger, more polydispersed and aggregated with an increase in oil fraction. Cross-linking with genipin increased the puncture strength of the gels vs. their uncross-linked counterparts and was necessary to prevent breakdown. Swelling of the emulsion gels demonstrated Fickian behaviour at all gelatin: oil ratios. Indomethacin release followed Fickian diffusion at higher oil fractions only, demonstrating coupled Fickian and super-Case-II transport at lower oil ratios (5:1, 5:2 and 5:3). Overall, the introduction of a dispersed oil phase within a hydrogel was exploited for the release of hydrophobic bioactive compounds, with tailoring of composition used to significantly alter release kinetics. [ABSTRACT FROM AUTHOR]

Diabetes mellitus (DM), a clinical manifestation characterized by chronic hyperglycaemia, is often ascribed to either a defect in insulin secretion, insulin resistance or both. Ayurveda (Indian Traditional Medicinal System) have shown promising results in the treatment of diabetes using various plants and herbs with negligible side effects and cost effective treatment. However, only a limited number of these plants have been explored and scientifically validated for their hypoglycemic effect. This review highlights some of the plants being commonly used in India for their hypoglycaemic effects. [ABSTRACT FROM AUTHOR]

The effects of ingestion of flaxseed gum on blood glucose and cholesterol, particularly low-density lipoprotein cholesterol, in type 2 diabetes were evaluated. Flaxseed gum was incorporated in wheat flour chapattis. Sixty patients of type 2 diabetes were fed a daily diet for 3 months, along with six wheat flour chapattis containing flaxseed gum (5 g), as per the recommendations of the American Diabetic Association. The control group (60 individuals) consumed an identical diet but the chapattis were without gum. The blood biochemistry profiles monitored before starting the study and at monthly intervals showed fasting blood sugar in the experimental group decreased from 154 ± 8 mg/dl to 136 ± 7 mg/dl (P=0.03) while the total cholesterol reduced from 182 ± 11 mg/dl to 163 ± 9 mg/dl (P=0.03). Results showed a decrease in low-density lipoprotein cholesterol from 110 ± 8 mg/dl to 92 ± 9 mg/dl (P=0.02). The study demonstrated the efficacy of flax gum in the blood biochemistry profiles of type 2 diabetes. [ABSTRACT FROM AUTHOR]