Scaffold materials testing

For newly developed, as yet unapproved, novel biomaterial scaffolds, the regulatory preclinical guidelines developed for device materials evaluation are particularly useful in guiding the pre-clinical program of a neo-organ product. In general, the following preclinical tests should be included for such scaffold materials acute, subchronic, and chronic toxicity irritation to... 

The entry of a TE prototype into clinical testing can be accelerated when previously tested technologies are used (eg, an approved scaffold material, a cell processing method) because the number of variables to be tested in product prototyping and preclinical testing is significantly reduced. 

Scaffold Materials Most materials tested in research and development were medically approved biomaterials, designed and approved for other applications such as sutures. 

Silk fibers or monolayers of silk proteins have a number of potential biomedical applications. Biocompatibility tests have been carried out with scaffolds of fibers or solubilized silk proteins from the silkworm Bombyx mori (for review see Ref. [38]). Some biocompatibility problems have been reported, but this was probably due to contamination with residual sericin. More recent studies with well-defined silkworm silk fibers and films suggest that the core fibroin fibers show in vivo and in vivo biocompatibility that is comparable to other biomaterials, such as polyactic acid and collagen. Altmann et al. [39] showed that a silk-fiber matrix obtained from properly processed natural silkworm fibers is a suitable material for the attachment, expansion and differentiation of adult human progenitor bone marrow stromal cells. Also, the direct inflammatory potential of silkworm silk was studied using an in vitro system [40]. The authors claimed that their silk fibers were mostly immunologically inert in short and long term culture with murine macrophage cells. 

Significant developments have occurred in recent years in the fields of biopolymers and biomaterials. New synthetic materials have been synthesized and tested for a variety of biomedical and related applications from linings for artifical hearts to artifical pancreas devices and from intraocular lenses to drug delivery systems. Of particular interest in the future is the development of intelligent polymers or materials with special functional groups that can be used either for specialty medical applications or as templates or scaffolds for tissue regeneration. 

As well as being used as a scaffold for tissue engineering, Hutchens et al. [64] described the creation of a calcium-deficient hydroxyapatite, the main mineral component of bone. Calcium phosphate particles were precipitated in BC by consecutive incubation of calcium chloride and sodium phosphate solutions. Initial tests with osteoblasts in the in vitro evaluation showed that solid fusion between the material and the bone tissue is possible. Hence, this material is a good candidate for use as a therapeutic implant to regenerate bone and heal osseous damage. 

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