The effect of starch-based biomaterials on leukocyte adhesion and activation in vitro

Abstract

Leukocyte adhesion to biomaterials has long been recognised as a key element to determine their inflammatory potential. Results regarding leukocyte adhesion and activation are contradictory in some aspects of the material's effect in determining these events. It is clear that together with the wettability or hydrophilicity/hydrophobicity, the roughness of a substrate has a major effect on leukocyte adhesion. Both the chemical and physical properties of a material influence the adsorbed proteins layer which in turn determines the adhesion of cells.In this work polymorphonuclear (PMN) cells and a mixed population of monocytes/macrophages and lymphocytes (mononuclear cells) were cultured separately with a range of starch-based materials and composites with hydroxyapatite (HA). A combination of both reflected light microscopy and scanning electron microscopy (SEM) was used in order to study the leukocyte morphology. The quantification of the enzyme lactate dehydrogenase (LDH) was used to determine the number of viable cells adhered to the polymers. Cell adhesion and activation was characterised by immunocytochemistry based on the expression of several adhesion molecules, crucial in the progress of an inflammatory response.This work supports previous in vitro studies with PMN and monocytes/macrophages, which demonstrated that there are several properties of the materials that can influence and determine their biological response. From our study, monocytes/macrophages and lymphocytes adhere in similar amounts to more hydrophobic (SPCL) and to moderately hydrophilic (SEVA-C) surfaces and do not preferentially adhere to rougher substrates (SCA). Contrarily, more hydrophilic surfaces (SCA) induced higher PMN adhesion and lower activation. In addition, the hydroxyapatite reinforcement induces changes in cell behaviour for some materials but not for others.

An In Vivo Study of the Host Response to Starch‐Based Polymers and Composites Subcutaneously Implanted in Rats

“…The results obtained for the blend of starch with cellulose acetate (SCA), with the lowest level of inflammation for the studied implantation periods, correlated well with in vitro results, [51] which showed a lower number of cells from a mixed population of monocytes/macrophages and lymphocytes and a reduced amount of activated macrophages on that material. No T lymphocytes were found at the interface or in the tissues adjacent to the implant.…”

Silk Fibroin Processing and Thrombogenic Responses

“…Samples COH and BOH (data not shown) in AFM analysis had the most corrugated surface morphology (Fig. 2) and the highest number of adhered cells was seen on these films [33][34][35]. The approach taken in the present paper, to compare source material and processing routes to biological responses, is unique in terms of the degradable biomaterial field.…”

New biomineralization strategies for the use of natural-based polymeric materials in bone-tissue engineering

“…One of the main advantages of these materials for bone-related applications is the combination of mechanical performance with degradation behaviour (Azevedo, et al, 2003;Mano, et al, 2004;Reis, et al, 1996;Reis, et al, 1997b;Sousa, et al, 2002;Vaz, et al, 2001). Additionally, it has been shown (Gomes, et al, 2001;Marques, et al, 2002;Marques, et al, 2003;Marques, et al, 2005a;Marques, et al, 2005b;Mendes, et al, 2003;Mendes, et al, 2001;Reis, et al, 1996;Salgado, et al, 2004;Salgado, et al, 2005) that these materials can comply with the biocompatibility requirements of a biomaterial, as defined in international standards, which is not typical of biodegradable systems. Compared to other biodegradable polymers on the market, starch-based blends are the cheapest, and are available in much larger quantities from several renewable plant sources.…”