Globular and Fibrous Proteins Modified with Deep Eutectic Solvents: Materials for Drug Delivery

Proteinaceous materials have numerous structures, many of which aid in the roles they perform. Some need to impart strength while others need elasticity or toughness. This study is the first to investigate the modification of both globular and fibrous protein, namely, zein, soy protein and gelatin, using deep eutectic solvents (DES) to form bioplastics, which may have application in drug delivery systems. The effects of DES content on the thermal and mechanical properties of the material were determined. Zein and soy are globular proteins, which both showed a significant change in the properties by the addition of DES. Both of these materials were, however, weaker and less ductile than the starch based materials previously reported in the literature. The material made from gelatin, a fibrous protein, showed variable properties depending on how long they were in contact with each other before pressing. Conductivity and NMR measurements indicate the existence of a continuous liquid phase, which are useful in the demonstrated application of transdermal drug delivery systems. It is shown that pharmaceutical DESs can be gelled with gelatin and this method is three times faster at delivering a pharmaceutical active ingredient across the skin barrier than from a corresponding solid formulation.

Marine Spongin: Naturally Prefabricated 3D Scaffold-Based Biomaterial

The biosynthesis, chemistry, structural features and functionality of spongin as a halogenated scleroprotein of keratosan demosponges are still paradigms. This review has the principal goal of providing thorough and comprehensive coverage of spongin as a naturally prefabricated 3D biomaterial with multifaceted applications. The history of spongin's discovery and use in the form of commercial sponges, including their marine farming strategies, have been analyzed and are discussed here. Physicochemical and material properties of spongin-based scaffolds are also presented. The review also focuses on prospects and trends in applications of spongin for technology, materials science and biomedicine. Special attention is paid to applications in tissue engineering, adsorption of dyes and extreme biomimetics.

ISOLATION, CHARACTERIZATION AND IMMUNOCHEMICAL STUDIES ON FIBROUS PROTEINS FROM COWRY SHELL (CYPRAEA MONETA, LINNAEUS)

BACKGROUND

Biomaterials are non-drug substances used to treat, enhance or replace functions of body tissues or organs. Natural sources of biomaterials have recently become the focus of several research activities. Cowry shell constitutes one of the most promising natural sources of biomaterials because of its chemical stability, biodegradability and biocompatibility in the body. However, its applications may be limited due to immunogenic and toxic responses that may occur following implantation, hence this study.

MATERIALS AND METHODS

Crude fibrous protein extracted with citrate buffer from pulverised cowry shells (Cypraea moneta (L)), was resolved into two components (CSP1 and CSP2) by gel filtration. Immunological studies were performed with antisera obtained from rabbits by double immunodiffusion and immunoelectrophoresis techniques. Mice treated with the proteins were observed for signs of toxicity and their liver, kidney, lungs and spleen were processed histologically.

RESULTS

The native molecular weight of CSP1 and CSP2 determined by gel filtration were 91kDa and 33kDa respectively. CSP1 and CSP2 displayed single bands on SDS-PAGE with subunit molecular weight values of 19kDa and 19.5kDa respectively. Antisera obtained from rabbits immunised with the crude citrate buffer extracts precipitated the antigen in double immunodiffusion tests. Histopathological examinations revealed a dose-dependent damaging effect of the shell proteins on liver, kidney, lung and spleen tissues of the treated mice.

CONCLUSION

This study showed that cowry shells contain fibrous proteins which are immunogenic and toxic in mice at relatively high concentrations, causing visible organ damage without concurrent physical manifestations.

Studies on two closely related species of octocorallians: biochemical and molecular characteristics of the organic matrices of endoskeletal sclerites

Two species of alcyonarian corals, Lobophytum crassum and Sinularia polydactyla, are closely related to each other. It is reported that the calcified organic substances in the skeletons of both contain a protein-polysaccharide complex playing a key role in the regulation of biocalcification. However, information on the matrix proteins of endoskeletal sclerite has been lacking. Hence we studied the proteinaceous organic matrices of sclerites for both species, to analyze the sequences and the functional properties of the proteins present. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the preparations showed four bands of proteins with apparent molecular masses of 102, 67, 48, and 37 kDa for L. crassum and seven bands of 109, 83, 70, 63, 41, 30, and 22 kDa for S. polydactyla. A major protein band of about 67 kDa in L. crassum and two bands of proteins of about 70 and 63 kDa in S. polydactyla yielded N-terminal amino acid sequences. Periodic acid-Schiff staining indicated that the 67-kDa protein in L. crassum, and 83- and 63-kDa proteins in S. polydactyla were glycosylated. For detection of calcium binding proteins, a Ca(2+) overlay analysis was conducted in the extract via (45)Ca autoradiography. The 102- and 67-kDa calcium binding proteins in L. crassum, and the 109- and 63-kDa Ca(2+) binding proteins in S. polydactyla were found to be radioactive. An assay for carbonic anhydrase (CA), which is thought to play an important role in the process of calcification, revealed specific activities. Newly derived protein sequences were subjected to standard sequence analysis involving identification of similarities to other proteins in databases. The significantly different protein expressions and compositional analysis of sequences between two species were demonstrated.