Standards and Guidelines for Biopolymers in Tissue‐Engineered Medical Products

Abstract

The American Society for Testing and Materials (ASTM) is making a concerted effort to establish standards and guidelines for the entire field of tissue‐engineered medical products (TEMPS). Safety, consistency, and functionality of biomaterials used as matrices, scaffolds, and immobilizing agents in TEMPS are a concern. Therefore, the ASTM has established a number of task groups to produce standards and guidelines for such biomaterials. Alginate is a naturally occurring biomaterial used for immobilizing living cells to form an artificial organ, such as encapsulated pancreatic islets. In order to aid in successful clinical applications and to help expedite regulatory approval, the alginate used must be fully documented. The ASTM alginate guide gives information on selection of testing methodologies and safety criteria. Critical parameters such as monomer content, molecular weight, and viscosity, in addition to more general parameters, such as dry matter content, heavy metal content, bioburden, and endotoxin content are described in the ASTM document. In a like manner, the characterization parameters for chitosan, a bioadhesive polycationic polysaccharide, are described in a separate guide. For chitosan, the degree of deacetylation is of critical importance. Control of protein content and, hence, potential for hypersensitivity, endotoxin content, and total bioburden are important in chitosan preparations for TEMPS. Together these two guides represent part of the effort on behalf of the ASTM and other interested parties to ensure quality and standardization in TEMPS.

Antioxidative effect of folate–modified chitosan nanoparticles

“…Chitosan (CS) is the deacetylated form of chitin. CS is a linear polysaccharide, composed of glucosamine and N-acetyl glucosamine linked in a 毬 linkage [1,2] . Molecular weight and degree of deacetylation are the main factors affecting the particle size, particles formation and aggregation.…”

Adding Functions to Biomaterial Surfaces through Protein Incorporation

“…[18] One of the most commonly encountered reactions to many materials in vivo is a classical foreign body response in which a rapid, nonspecific adsorption of proteins occurs, followed by the chemotactic attraction of immune and inflammatory cells. [19] As a result, implanted biomaterials can become encapsulated by fibrous tissue, which prevents their interactions with surrounding cells and materials, though device or material design can be optimized to minimize the foreign body response.…”

Histological and hormonal characteristic of microencapsulated human parathyroid tissue in long-term culture

“…Îäíàê âèêîðèñòàííÿ àëüã³íàòó â ôàðìà-öåâòè÷í³é òà/àáî á³îìåäè÷í³é ãàëóçÿõ âè-ìàãຠòàêîae îáîâÿçêîâî¿ â³äïîâ³äíîñò³ âñ³õ êîìïîíåíò ì³êðîêàïñóë êðèòåð³ÿì áåçïåêè, çîêðåìà American Society for Testing and Materials òà US Food and Drug Administration [7]. Äîñë³äaeåííÿ â öüîìó íàïðÿìêó ïðîäîâaeóþòüñÿ.…”