Bone defects have always been an important cause of threat to human health, and artificial biomimetic bone repair replacement materials are currently one of the most effective and feasible solution approaches to treat bone damage. To develop artificial bone biomimetic materials, an in vitro biomimetic mineralization system must be constructed first to study in vitro biomimetic mineralization mechanism of natural bone matrix. Collagen is a template for mineralization, and its properties such as crosslinking degree, diameter, osmotic pressure, and surface charge can all directly affect mineralization progress. The biochemical and mechanical environments in which mineralization occurs are also quite distinct in their effects on mineralization process, particularly noncollagenous proteins and fluid shear stress (FSS). FSS is considered to be the main mechanical stimulation of bone tissues in micro-environment, which is of great significance to bone growth, repair and health maintenance. FSS at different levels and loading regimes has significant effects on transformation of amorphous calcium phosphate to bone apatite, self-assembly and directional alignment of collagen fibrils, and formation of hierarchical intrafibrillar mineralization. In this paper, the factors affecting collagen mineralization and their mechanism were summarized, with focus on regulation of FSS on collagen mineralization, and development direction in future was also prospected.

Objective To investigate the value of vacuum sealing drainage (VSD) combined with external fixator in patients with severe damage of lower extremities by limb salvage.Methods Totally 100 patients with severe damage of lower extremities were treated with limb salvage,and they were divided into observation group and control group.Dressing replacement combined with external fixator was used in control group,while the observation group was treated with VSD combined with external fixation.The recovery and complications were observed and analyzed.Results The average operation times,bacterial negative-conversing time,wound healing time and fracture healing time in observation group were significantly better than those in control group (P ＜ 0.05).The incidence rate of osteomyelitis,deep infection,complications and amputation in observation group were significantly lower than the control group (P ＜ 0.05).Conclusion VSD combined with external fixation can effectively maintain fracture stability and promote wound healing in patients with severe damage of lower extremities by limb salvage.

Objective To investigate the value of vacuum sealing drainage (VSD) combined with external fixator in patients with severe damage of lower extremities by limb salvage.Methods Totally 100 patients with severe damage of lower extremities were treated with limb salvage,and they were divided into observation group and control group.Dressing replacement combined with external fixator was used in control group,while the observation group was treated with VSD combined with external fixation.The recovery and complications were observed and analyzed.Results The average operation times,bacterial negative-conversing time,wound healing time and fracture healing time in observation group were significantly better than those in control group (P ＜ 0.05).The incidence rate of osteomyelitis,deep infection,complications and amputation in observation group were significantly lower than the control group (P ＜ 0.05).Conclusion VSD combined with external fixation can effectively maintain fracture stability and promote wound healing in patients with severe damage of lower extremities by limb salvage.