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  5. Volume 7, Issue 2, 2024

Current Applied Polymer Science - Volume 7, Issue 2, 2024

Volume 7, Issue 2

Volume 7, Issue 2, 2024

    • The Self-assembly of Single Amino Acids and Materials Rich in a Particular Amino Acid

      https://doi.org/10.2174/0124522716338272241107051010

      Diseases can result from an excess or deficit of amino acids in the blood. The smallest biomolecules that can self-assemble are amino acids. Fifteen amino acids, phenylalanine, tryptophan, histidine, glycine, alanine, valine, serine, isoleucine, proline, cysteine, glutamic acid, methionine, threonine, tyrosine, and lysine, have been observed to self-assemble out of the twenty amino acid forms. A disorder known as “hyperaminoacidemia” can result from elevated blood levels of amino acids, while there are rare exceptions, such as phenylketonuria (high phenylalanine) and histidinemia (high histidine concentration). Increased level of amino acids in the blood is the source of all these disorders, which can manifest neurological symptoms, such as mental retardation, convulsions, epilepsy, immobility, and developmental delay. The high concentrations of amino acids in the body are caused by decreased activity of enzymes that are responsible for breaking down amino acids, a phenomenon that has been extensively studied in relation to mutations in these enzymes. Phenylketonuria, a neurological disorder caused by phenylalanine self-assembly, is associated with high phenylalanine levels. Neurodegeneration, typified by tryptophan self-assembly, is caused by an abnormal accumulation of tryptophan, which has been connected to hypertryptophanemia. There is uncertainty about the molecular mechanism underlying diseases caused by elevated levels of every other amino acid in our bodies. The self-assembly of various single amino acids and materials rich in a specific amino acid is discussed in this review article, along with the consequences and the variety of structures that are created, as well as the effects of factors like temperature, pH, concentration, and so forth.

    • Crack Growth Behavior in Metal-elastomer Bonding Interface under Cyclic Deformation

      https://doi.org/10.2174/0124522716324824240905113526
      Introduction

      Metal-elastomer adhesion becomes increasingly important for elastomer parts comprising metal components, such as packer elements for Blowout Preventers (BOP), completion packers, metal encapsulated seals, and stator/rotors. As the bonding between metal and elastomer deteriorates under cyclic deformation, cracks can appear on the adhesion interface and reduce the function of the parts.

      Methods

      Thus, the fatigue performance or crack growth rate of the metal-elastomer adhesion affects the service life of the whole elastomer part. In this study, the metal-elastomer bonded parts were fabricated and evaluated under cyclic shear and peel deformation at both room temperature and high temperature.

      Results

      The crack growth rates (/) on the metal-elastomer interface were measured based on the strain energy release rate () for different elastomers with both excellent and poor adhesion, and the API lifetime of BOP packers were therefore estimated.

      Conclusion

      The results indicated that the crack growth rates in the adhesion interface can be correlated with the API lifetime of BOP packers, and the elastomer with a low crack growth rate will have a better fatigue life for the BOP application.

    • Optimization and Characterization of Mucoadhesive Buccal Films using Mimosa Seed-based Natural Polymer for Controlled Drug Release: A Sustainable Approach

      https://doi.org/10.2174/0124522716331619240830064412
      Background

      The present study attempted to develop cost-effective, biocompatible and biodegradable mucoadhesive buccal films exploring and using seed polymer, marking its potential as a sustainable drug delivery in pharmaceutical development.

      Methods

      The extracted polymer was characterized for solubility, viscosity, loss on drying, pH, swelling index, starch, and mucilage ingredients. Compatibility between the polymer, drug, and excipients was assessed using FTIR analysis. Buccal film trial batches were formulated using the film casting technique and were optimized using the 23 full factorial design. Optimized formulation was characterized for drug release, permeability, mucoadhesive study, similarity, and difference factor along with histological and stability study.

      Results

      The polymer’s pH, loss on drying, swelling index, and viscosity were 6.2, 6.8%, 81.77%, and 50,000 cP respectively. FTIR studies showed the compatibility between natural polymer, the model drug metoprolol succinate, and the excipients used. The early trial batches of polymeric films showed an extended drug release comparable to the standard polymers with a good permeability flux of 0.4048 ± 0.081 mcg*cm-2*h-1. The optimized film provided a controlled release of 52.31 ± 0.035% for more than 8 h following zero order kinetics. Mucoadhesive strength was found to be 32.25 ± 0.29 g. The similarity factor f2 (90.2) and difference factor f1 (8.197) indicated no significant difference compared to the standard formulation. Histological study demonstrated the non-irritant nature of the films and stability was established from the stability studies.

      Conclusion

      Thus, a sustainable approach using natural polymeric buccal films was found promising for mucoadhesion and controlled release.

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