Glutaraldehyde-crosslinked poly(vinyl alcohol) hydrogel discs for the controlled release of antidiabetic drug

Hydrogel-based Drug Delivery System in Diabetes Management

BACKGROUND

It is estimated that there are over 200 million people living with diabetes mellitus (DM) all over the world. It is a metabolic condition caused by decreased insulin action or secretion. Diabetes Mellitus is also known as Type 2 Diabetes Mellitus. Type 1 diabetes mellitus and type 2 diabetes mellitus are the two most common types of DM. Treatment for type 1 diabetes often consists of insulin replacement therapy, while treatment for type 2 diabetes typically consists of oral hypoglycemics.

OBJECTIVES

Conventional dosing schedules for the vast majority of these medications come with a number of drawbacks, the most common of which are frequent dosing, a short half-life, and low bioavailability. Thus, innovative and regulated oral hypoglycemic medication delivery methods have been developed to reduce the limitations of standard dose forms.

METHODS

The studies and reviews published under the title were looked up in several databases (including PubMed, Elsevier, and Google Scholar).

RESULTS

Hydrogels made from biopolymers are three-dimensional polymeric networks that can be physically or chemically crosslinked. These networks are based on natural polymers and have an inherent hydrophilic quality because of the functional groups they contain. They have a very high affinity for biological fluids in addition to a high water content, softness, flexibility, permeability, and biocompatibility. The fact that these features are similar to those of a wide variety of soft living tissues paves the way for several potentials in the field of biomedicine. In this sense, hydrogels offer excellent platforms for the transport of medications and the controlled release of those drugs. Additionally, biopolymer-based hydrogels can be put as coatings on medical implants in order to improve the biocompatibility of the implants and to prevent medical diseases.

CONCLUSION

The current review focuses on the most recent advancements made in the field of using biopolymeric hydrogels that are physically and chemically crosslinked, in addition to hydrogel coatings, for the purpose of providing sustained drug release of oral hypoglycemics and avoiding problems that are associated with the traditional dosage forms of oral hypoglycemics.

Carboxymethyl Cellulose Entrapped in a Poly(vinyl) Alcohol Network: Plant-Based Scaffolds for Cartilage Tissue Engineering

Cartilage has a limited inherent healing capacity after injury, due to a lack of direct blood supply and low cell density. Tissue engineering in conjunction with biomaterials holds promise for generating cartilage substitutes that withstand stress in joints. A major challenge of tissue substitution is creating a functional framework to support cartilage tissue formation. Polyvinyl alcohol (PVA) was crosslinked with glutaraldehyde (GA), by varying the mole ratios of GA/PVA in the presence of different amounts of plant-derived carboxymethyl cellulose (CMC). Porous scaffolds were created by the freeze-drying technique. The goal of this study was to investigate how CMC incorporation and crosslinking density might affect scaffold pore formation, swelling behaviors, mechanical properties, and potential use for engineered cartilage. The peak at 1599 cm-1 of the C=O group in ATR-FTIR indicates the incorporation of CMC into the scaffold. The glass transition temperature (Tg) and Young's modulus were lower in the PVA/CMC scaffold, as compared to the PVA control scaffold. The addition of CMC modulates the pore architecture and increases the swelling ratio of scaffolds. The toxicity of the scaffolds and cell attachment were tested. The results suggest that PVA/CMC scaffolding material can be tailored in terms of its physical and swelling properties to potentially support cartilage formation.

Development of insect-proof starch adhesive containing encapsulated cinnamon oil for paper box adhesion to inhibit Plodia interpunctella larvae infestation

The objectives of this study were to develop insect-resistant adhesives and apply them to a cardboard packaging system for preventing Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) larvae infestation. Cinnamon essential oil (CO), an insecticide, was encapsulated with maltodextrin (CS/MD/CO), β-cyclodextrin (CS/β-CD/CO), and polyvinyl alcohol (CS/PVA/CO) in corn starch (CS) paste. This resulted in a sustained and gradual release of CO from the starch-based insect-proof adhesives. Penetration pathways of insects into corrugated cardboard boxes were investigated through the use of a screening test for infestation profiling. Microscopic images of encapsulated CO in an oil in water (O/W) emulsion were observed to confirm the morphology of the adhesives. Adhesion forces of CS, CS/CO, CS/MD/CO, CS/β-CD/CO, and CS/PVA/CO were determined to be 6.2 N, 4.0 N, 3.1 N, 6.0 N, and 5.8 N, respectively. Consequently, significant decreases of adhesion force in the CS/CO and CS/MD/CO were found to be due to the presence of the surfactant (Span^® 80) and the low adhesive properties of MD. The duration of the insecticidal activities of the developed adhesives was evaluated by measuring their release rates for 14 days and repellent profiles up to 24 hr and 40 days. As a result, CS/β-CD/CO and CS/PVA/CO were found to have an inhibited rapid release and sustained repellent profiles. In conclusion, CS/β-CD/CO and CS/PVA/CO were determined to be suitable for encapsulation models and could be applied to industrial cardboard containers to prevent cases of insect invasion. PRACTICAL APPLICATION: Corn starch-based natural adhesives with an insect-proof property were applied to food containers consisted of corrugated cardboard boxes. Cornflake cereal packaging using insect-proof corrugated cardboard successfully prohibited pest invasion in commercial food distribution simulation model. Developed insecticidal adhesives are able to control insect penetration in distribution and storage steps.

Rapid immobilization of viable Bacillus pseudomycoides in polyvinyl alcohol/glutaraldehyde hydrogel for biological treatment of municipal wastewater

A new approach for easy synthesis of Bacillus pseudomycoides immobilized polyvinyl alcohol (PVA)/glutaraldehyde (GA) hydrogel for application in a wastewater treatment system is reported. Optimization studies revealed that GA/PVA mass ratio of 0.03 and acidic pH of 2 were required for hydrogel synthesis and eventually for bacterial cell immobilization. The synthesized crosslinked matrix possessed a pore size suitable for microbial cell entrapment while maintaining cell accessibility to external environment for bioremediation. Possible crosslinking and bacterial cell immobilization in the hydrogel were evidenced by FTIR, XRD, and SEM studies, respectively. Further, the extent of crosslinking of GA with PVA was investigated and confirmed by transmittance and permeability experiments. The viability and proliferation of hydrogel embedded cells (after 25 days) was confirmed by confocal fluorescence microscopy which also indicated that acidic pH of polymer solution did not affect the immobilized live cells. B. pseudomycoides immobilized hydrogel were demonstrated to be effective for treatment of municipal wastewater and reduced biochemical oxygen demand (BOD), chemical oxygen demand (COD), and protein content below the recommended levels. Overall, the results from this bench-scale work show that employing bacteria-embedded PVA/GA hydrogel for the treatment of municipal wastewater yield promising results which should be further explored in pilot/field-scale studies.