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

Abstract

Implant failure is one of the major concerns in the biomaterials field. Several factors have been related to the fail but in general these biomaterials do not exhibit comparable physical, chemical or biological properties to natural tissues and ultimately, these devices can lead to chronic inflammation and foreign-body reactions. Starch-based biodegradable materials and composites have shown promising properties for a wide range of biomedical applications as well as a reduced capacity to elicit a strong reaction from immune system cells in vitro. In this work, blends of corn starch with ethylene vinyl alcohol (SEVA-C), cellulose acetate (SCA) and polycaprolactone (SPCL), as well as hydroxyapatite (HA) reinforced starch-based composites, were investigated in vivo. The aim of the work was to assess the host response evoked for starch-based biomaterials, identifying the presence of key cell types. The tissues surrounding the implant were harvested together with the material and processed histologically for evaluation using immunohistochemistry. At implant retrieval there was no cellular exudate around the implants and no macroscopic signs of an inflammatory reaction in any of the animals. The histological analysis of the sectioned interface tissue after immunohistochemical staining using ED1, ED2, CD54, MHC class II and alpha/beta antibodies showed positively stained cells for all antibodies, except for alpha/beta for all the implantation periods, where it was different for the various polymers and for the period of implantation. SPCL and SCA composites were the materials that stimulated the greatest cellular tissue responses, but generally biodegradable starch-based materials did not induce a severe reaction for the studied implantation times, which contrasts with other types of degradable polymeric biomaterials.

The in vivo assessment of a novel scaffold containing heparan sulfate for tissue engineering with human mesenchymal stem cells

“…This pattern is commonly found in cases of chronic inflammation caused by subcutaneous implantation of polymeric biomaterials (De Jong et al 2005;Hagerty et al 2000;Marques et al 2005;Rosengren et al 1997). Marques and colleagues (Marques et al 2005) studied the host response to a variety of starchbased polymers implanted in rats and observed that ED1-positive macrophages immediately migrated to, and layered the implant surface with a thickness dependent on the material type. In our study, no difference in the thickness of the layer of ED1-positive macrophages encapsulating the various implants was found, regardless of the concentration of HS incorporated, the presence of seeded hOPs, or the presence of BMP.…”

“…This would seem to suggest that the PCL material is mediating the inflammatory response, although a more detailed time-course study is needed to confirm this. Due to their close association with the implant surface, these ED1-positive macrophages are thought to play an active role in phagocytosis (Marques et al 2005). The accumulation of mature ED2-positive macrophages at the implantation site has been reported to occur at a much slower rate; they are thought to play a role in tissue regeneration and recruitment of additional macrophages from the surrounding vasculature (Rhodes et al 1997).…”

Hybrid Biodegradable Films from Collagenous Wastes and Natural Polymers for Biomedical Applications

“…Researchers have shown that a blend of starch with ethylene vinyl alcohol, cellulose acetate, polycaprolactone, hydroxyapatite, bioactive glasses and glassceramics [41][42][43][44][45] can be used for several biomedical applications such as bone fixation/replacement [46,47], filling of bone defects, partially degradable bone-cements [48][49][50], drug delivery carriers [51,52] and tissue engineering scaffolds [53][54][55]. On the other hand, soy protein is generally known as storage protein and it constitutes around 50% of soy flour.…”

Development of a bioactive glass fiber reinforced starch–polycaprolactone composite

“…Starch has been blended at least with ethylene vinyl alcohol, 1-2,4-11 cellulose acetate, 2,[4][5][6][7]12 polylactide, 5,13 and poly-e-caprolactone (SPCL). 1,[5][6][7]14,15 Starch-based polymers are nowadays manufactured for various applications, for example to agriculture applications and packaging segments. 16 In addition they have shown to have good potential to be used in different biomedical applications, especially in bone applications such as tissue engineering scaffolds, bone cements, drug-delivery applications, or bone fixation devices.…”

“…16 In addition they have shown to have good potential to be used in different biomedical applications, especially in bone applications such as tissue engineering scaffolds, bone cements, drug-delivery applications, or bone fixation devices. 1,3,4,[6][7][8]14,15 SPCL is a potential new biocompatible and biodegradable blend which is studied to be used in bone applications. It has shown relatively good biocompatibility.…”