Integrated image-based design and solid free-form fabrication can create scaffolds that attain desired elasticity and permeability while fitting any 3D craniofacial defect. The scaffolds could be manufactured from degradable polymers, calcium phosphate ceramics and titanium. The designed scaffolds supported significant bone regeneration for all pore sizes ranging from 300 to 1200 microns. These results suggest that designed scaffolds are clinically applicable for complex craniofacial reconstruction.

Computationally designed scaffolds can support masticatory function in a large animal model as well as both osseous and cartilage regeneration. Our group is continuing to evaluate multiple implant designs in both young and mature Yucatan minipig animals.

Internal architecture has a direct impact on the mechanical and biological behaviors of porous hydroxyapatite (HA) implants. However, traditional processing methods provide very minimal control in this regard. This paper reviews a novel processing technique developed in our laboratory for fabricating scaffolds with controlled internal architectures. The preliminary mechanical property and in vivo evaluation of these scaffolds are also presented.

Summary: Hydroxyapatite bioceramic was used for the manufacture of an orbital floor prosthesis from spiral CT data acquired transaxially at 1-mm beam collimation, pitch of 1, and 0.2-mm reconstruction intervals. CT data were converted to vector file format for subsequent prosthesis manufacture on a stereolithography machine. The orbital floor prosthesis was engrafted onto an acrylic model of the orbit as a qualitative indication of its overall accuracy. High anatomic accuracy was achieved, as determined by visual inspection. Cross-hatching of the vector file data allowed a porous internal architecture of the prosthesis. Refinements in chemical structure of the hydroxyapatite bioceramic are expected to enhance mechanical properties.

We report finding a simple method to partially reproduce the characteristic process of molting that takes place in invertebrates using human skin explants in vitro. In this method, human skin explants discarded from regular plastic surgery procedures were kept, submersed, in regular growth medium for 10 days at 4°C. After that period, the skin explants were cultured at the air-liquid interface for another 10 days. Histological analysis of the skin revealed the formation of one full epidermal structure and an additional intermediate epidermal structure containing a putative stratum corneum, superimposed one of top of the other, in which we consider an equivalent model of "molting" or "ecdysis". Basic analysis of cell proliferation and differentiation of the explants at different stages of the process are briefly presented. We believe this model can be used in the study of certain human skin diseases as well as in comparative animal physiology.