BACKGROUND:Tissue engineering bone application for repairing critical-size segmental defects is stil in research stage. The ideal construction methods have not yet been found.
OBJECTIVE:To review the research literatures on tissue engineering bone scaffold material, its shape and effect on the loading of seeding cells, seek appropriate engineered bone scaffolds which are capable of loading a large number of cells effectively and probably, and provide a new way of repairing segmental bone defects.
METHODS:The first author performed a data retrieval of PubMed and Wanfang databases from 1994 to 2013, to search the articles addressing the construction method of tissue engineering bone scaffold, and reviewed the literatures systematical y.
RESULTS AND CONCLUSION:A total of 379 references were retrieved, including 161 articles in Chinese and 218 articles in English. According to the inclusion and exclusion criteria, 53 articles were final y involved in the analysis. The analysis results indicated that, the needed volume of bone tissue engineering scaffolds for critical-sized section bone defect reconstruction is big, which needs to load a huge number of seed cells. If there is no suitable forms and shapes for celladhesion, the property of so-cal ed engineered bone is similar to pure artificial bone implants. The effective load of seed cells on engineering bone scaffold material and keeping the activity is the first step in clinical practice, as wel as the important guarantee for loading bioactive seed cells. Hence, a more simple and accurate detection method for loading cellquantity is needed. Looking into the retrieved content, effective load cellquantity and its bioactivity are detected by indirect methods, supporting the effectiveness of cellseeding. Some methods can guarantee the cellquantity and seeding pattern, the real load is unknown as wel as the activity. Fabricating engineering bone scaffold into special form and shape are easy to effective seeding, proliferation and maintaining the biomechanical performance, inducing osteogenesis, and final y detecting the load cellquantity and activity on the scaffold through the simple and direct method.

BACKGROUND:The effects of engineered bone scaffold containing seeding cels with different shapes to repair bone defect are varied, while the loaded cellquantity is the important factor influencing the curative effect, but which is rarely reported. OBJECTIVE:By preparing self-made corrugated tissue-engineered bone scaffold and other three forms of bone tissue engineering scaffolds, to study the quantity of loaded cels on different scaffolds and osteogenesis of corrugated tissue-engineered bone scaffold so as to discuss the advantages and features of self-made corrugated tissue-engineered bone scaffold. METHODS: (1) Experimentin vitro: There were four kinds of scaffolds with the same volume and samples: calcium phosphate cement (CPC) corrugated surface scaffold group, smooth surface scaffold group, cylindrical scaffold group and porous cylindrical scaffold with holow tubes group, in which the latter three groups are control ones. A certain volume with same density of rabbit bone marrow mesenchymal stem cels (BMSCs) suspension after osteogenesis induction was seeded onto the scaffolds. After incubation, culture, digestion and colection, cellquantity was counted, absorbance value was finaly detected and cellactivity was proofed by alkaline phosphatase and alizarin red staining. (2) Experimentin vivo: New Zealand rabbits were randomly and equaly divided into recombinant human bone morphogenetic protein-2 (rhBMP-2)/CPC/BMSCs corrugated scaffold group, pure CPC corrugated scaffold group and cancelous bone implant group. Three kinds of scaffold implants with the same volume were inserted into the area between rabbit’s L5, 6 transverse processes bilateraly. At 4, 8, 12 weeks postoperatively, gross and histological observation was performed. RESULTS AND CONCLUSION:(1)Experimentin vitro: The drip of cellsuspension steadily stayed on the surface of corrugated scaffold because of corrugated shape groove and the surface tension of the liquid. The amount of cels per sample digested down from the CPC corrugated surface scaffold was significantly more than that from the other three groups (P < 0.05), while the absorbance values did not differ (P > 0.05). (2) Experimentin vivo: At each time point the osteogenesis quantity of rhBMP-2/CPC/BMSCs corrugated scaffold group was more than that of the pure CPC corrugated scaffold group (P < 0.05), while there was no difference from the cancelous bone implant group (P > 0.05). These findings indicate that the characteristics of the self-made corrugated engineered bone scaffold are beneficial to seed cellloading, which supports a large number of osteogenesis and provides feasibility to promote the healing of segmental bone defects.

Serious diseases and other negative events bring serious physical and mental damage to individuals, but there are still some individuals can construct positive meaning of life from adversity, which is closely related to the role of benefit finding. According to the theory of stress system, if negative events such as disease are taken as stressors, benefit finding can be regarded as a good manifestation of individual psychological stress response. At present, most of the studies on benefit finding are cross-sectional studies, ignoring the characteristics of its dynamic development and the predictive role of individual advantages and disadvantages on benefit finding. This paper reviews the predictive factors in the longitudinal study of benefit finding from protective factors and risk factors, in order to reduce the adverse effects of risk factors on the basis of exploring individual protective factors and provide a starting point for the research design of positive psychological cognitive intervention.