Table 1.

Summary of desirable scaffold properties.

Scaffold Characteristics	Desirable Features
Biocompatibility	•Non-toxic breakdown products •Non-inflammatory scaffold components, avoiding immune rejection
Biodegradability	•Controlled scaffold degradation which can complement tissue ingrowth whilst maintaining sufficient support •Degradable by host enzymatic or biological processes •Allows invading host cells to produce their own extracellular matrix
Bioactivity	•Scaffold materials that can interact with and bind to host tissue •Osteoconductive and osteoinductive properties •Inclusion of biological cues and growth factors to stimulate cell ingrowth, attachment and differentiation
Scaffold Architecture	•Interconnected pores allowing diffusion and cell migration •Microporosity to present a large surface area for cell-scaffold interactions •Macroporosity to allow cell migration and invasion of vasculature •Pore size tailored to target tissue and cells •Sufficient porosity to facilitate cell ingrowth without weakening mechanical properties •Inbuilt vascular channels to enhance angiogenesis in vivo
Mechanical Properties	•Compressive, elastic and fatigue strength comparable to host tissue allowing cell mechanoregulation to occur and structural integrity to remain in vivo •Scaffold material that can be readily manipulated in the clinical environment to treat individual patient bone defects