To modify the surface property of poly lactide-co-glycolide (PLGA) by biomimetic mineralization to construct a new kind of artificial bone. PLGA films and 3-diamensional (3-D) porous scaffolds hydrolyzed in alkaline solution were minerilized in SBF for 14 days. The morphology and composition of the mineral grown on PLGA were analyzed with SEM, FTIR and XRD. The porosity of the scaffolds was detected by using the liquid displacement method. The compressive strength of the scaffolds was detected by using a Shimadzu universal mechanic tester. An obvious mineral coating was detected on the surface of films and scaffolds. The main component of the mineral was carbonated hydroxyapatite (HA) similar to the major mineral component of bone tissues. The porosity of the un-mineralized and mineralized porous scaffolds was (84.86 +/- 8.52) % and (79.70 +/- 7.70) % respectively. The compressive strength was 0.784 +/- 0.156 N/mm2 in un-mineralized 3-D porous PLGA and 0.858 +/- 0.145 N/mm2 in mineralized 3-D porous PLGA. There were no significant differences between the mineralized and un-mineralized scaffolds (P > 0.05) in porosity and biomechanics. Biomimetic mineralization is a suitable method to construct artificial bone.
Biocompatible Materials ; Bone Substitutes ; Calcification, Physiologic ; Durapatite/metabolism ; Lactic Acid/*chemistry ; Polyglycolic Acid/*chemistry ; Polymers/*chemistry ; Porosity ; Tissue Engineering

Objective To study the reasons of seroma formation and long-term existence after modified radi-cal mastectomy ( MRM) .Methods The structure of fibrous lamina for seroma postoperative breast cancer was ana-lyzed by pathological methods;the composition of drainage fluids after MRM in the different postoperative time peri-ods was determined;and the structure of fibrous lamina following an experimental mastectomy model created in rats was investigated,which the process of fibrous lamina formation was imitated.Results There were three layer struc-tures in fibrous lamina,including fibrous leakage,capillaries and fiber lay.Hematology test results supported seroma for exudate.Animal model showed that with the extension of time,fibrous lamina thickened gradually.Conclusion It is capillaries in fibrous lamina that seroma long-standing histological basis.Maybe excising or destructing the structure of subcutaneous fibrous lamina,making the procedure of wound healing to begin again as soon as possible,which is a kind of effective method to solve the problem of seroma long-term existence after MRM.

To modify the surface property of poly lactide co-glycolide (PLGA) by biomimetic mineralization to construct a new kind of artificial bone. PLGA films and 3 diamensional (3-D) porous scaffolds hydrolyzed in alkaline solution were minerilized in SBF for 14 days. The morphology and composition of the mineral grown on PLGA were analyzed with SEM, FTIR and XRD. The porosity of the scaffolds was detected by using the liquid displacement method. The compressive strength of the scaffolds was detected by using a Shimadzu universal mechanic tester. An obvious mineral coating was detected on the surface of films and scaffolds. The main component of the mineral was carbonated hydroxyapatite (HA) similar to the major mineral component of bone tissues. The porosity of the un-mineralized and mineralized porous scaffolds was (84.86±8.52) % and (79.70±7.70) % respectively. The compressive strength was 0. 784±0. 156 N/mm2 in un-mineralized 3-D porous PLGA and 0. 858±0. 145 N/mm2 in mineralized 3-D porous PLGA. There were no significant differences between the mineralized and un-mineralized scaffolds (P＞0. 05) in porosity and biomechanics. Biomimetic mineralization is a suitable method to construct artificial bone.

Objective The magnetic beads direct adsorption method was used to extract the cell-free DNA (cfDNA) from three kinds of human humoral biological samples, including urine, saliva and blood, as to provide a reference for forensic cfDNA research and forensic inspection. Methods The cfDNA was isolated from humoral samples by centrifuging, and the cfDNA was extracted with the method of magnetic beads direct adsorption. Then the samples were sequentially amplified with Identifiler-Plus amplication kit, and the STR genotyping was detected by ABI 3500 Analyzer. Results The cfDNA was detected from all the three kinds of samples. The detection rate of cfDNA from the blood samples was 100%, the saliva was 90%, and the urine was 70%. Conclusion The results suggest that human humoral biological samples contain cfDNA. What's more, the magnetic beads direct adsorption method can be used to extract cfDNA efficiently and conveniently.