Objective To study the outcomes of nerve defect repair with the tissue engineered nerve, which is composed of the complex of SCs, 30% ECM gel, bFGF-PLGA sustained release microspheres, PLGA microfilaments and permeable poly (D, L-lacitic acid) (PDLLA) catheters. Methods SCs were cultured and purified from the sciatic nerves of 1-day-old neonatal SD rats. The 1st passage cells were compounded with bFGF-PLGA sustained release microspheres andECM gel, and then were injected into permeable PDLLA catheters with PLGA microfilaments inside. In this way, the tissueengineered nerve was constructed. Sixty SD rats were included. The model of 15-mm sciatic nerve defects was made, and then the rats were randomly divided into 5 groups, with 12 rats in each. In group A, autograft was adopted. In group B, the blank PDLLA catheters with PBS inside were used. In group C, PDLLA catheters, with PLGA microfilaments and 30% ECM gel inside, were used. In group D, PDLLA catheters, with PLGA microfilaments, SCs and 30% ECM gel inside, were used. In group E, the tissue engineered nerve was appl ied. After the operation, observation was made for general conditions of the rats. The sciatic function index (SFI) analysis was performed at 12, 16, 20 and 24 weeks after the operation, respectively. Eelectrophysiological detection and histological observation were performed at 12 and 24 weeks after the operation, respectively. Results All rats survived to the end of the experiment. At 12 and 16 weeks after the operation, group E was significantly different from group B in SFI (P lt; 0.05). At 20 and 24 weeks after the operation, group E was significantly different from groups B and C in SFI (P lt; 0.05). At 12 weeks after the operation, electrophysiological detection showed nerve conduct velocity (NCV) of group E was bigger than that of groups B and C (P lt; 0.05), and compound ampl itude (AMP) as well as action potential area (AREA） of group E were bigger than those of groups B, C and D (P lt; 0.05). At 24 weeks after the operation, NCV, AMP and AREA of group E were bigger than those of groups B and C (Plt; 0.05). At 12 weeks after the operation, histological observation showed the area of regenerated nerves and the number of myel inated fibers in group E were significantly differents from those in groups A, B and C (Plt; 0.05). The density and diameter of myel inated fibers in group E were smaller than those in group A (Plt; 0.05), but bigger than those in groups B, C and D (P lt; 0.05). At 24 weeks after the operation, the area of regenerative nerves in group E is bigger than those in group B (P lt; 0.05); the number of myel inated fibers in group E was significantly different from those in groups A, B, C (P lt; 0.05); and the density and diameter of myel inated fibers in group E were bigger than those in groups B and C (Plt; 0.05). Conclusion The tissue engineered nerve with the complex of SCs, ECM gel, bFGF-PLGA sustained release microspheres, PLGA microfilaments and permeables PDLLA catheters promote nerve regeneration and has similar effect to autograft in repair of nerve defects.
Objective To investigate the performance of loading naringin composite scaffolds and its effects on repair of osteochondral defects. Methods The loading naringin and unloading naringin sustained release microspheres were prepared by W/O/W method; with the materials of the attpulgite and the collagen type I, the loading naringin, unloading naringin, and loading transforming growth factor β1 (TGF-β1) osteochondral composite scaffolds were constructed respectively by " 3 layers sandwich method”. The effect of sustained-release of loading naringin microspheres, the morphology of the composite scaffolds, and the biocompatibility were evaluated respectively by releasingin vitro, scanning electron microscope, and cell counting kit 8. Forty Japanese white rabbits were randomly divided into groups A, B, C, and D, 10 rabbits each group. After a osteochondral defect of 4.5 mm in diameter and 4 mm in depth was made in the intercondylar fossa of two femurs. Defect was not repaired in group A (blank control), and defect was repaired with unloading naringin composite scaffolds (negative control group), loading naringin composite scaffolds (experimental group), and loading TGF-β1 composite scaffolds (positive control group) in groups B, C, and D respectively. At 3 and 6 months after repair, the intercondylar fossa was harvested for the general, HE staining, and toluidine blue staining to observe the repair effect. Western blot was used to detect the expression of collagen type II in the new cartilage. Results Loading naringin microspheres had good effect of sustained-release; the osteochondral composite scaffolds had good porosity; the cell proliferation rate on loading naringin composite scaffold was increased significantly when compared with unloading naringin scaffold (P<0.05). General observation revealed that defect range of groups C and D was reduced significantly when compared with groups A and B at 3 months after repair; at 6 months after repair, defects of group C were covered by new cartilage, and new cartilage well integrated with the adjacent cartilage in group D. The results of histological staining revealed that defects were filled with a small amount of fibrous tissue in groups A and B, and a small amount of new cartilage in groups C and D at 3 months after repair; new cartilage of groups C and D was similar to normal cartilage, but defects were filled with a large amount of fibrous tissue in groups A and B at 6 months after repair. The expression of collagen type II in groups C and D was significantly higher than that in groups A and B (P<0.05), but no significant difference was found between groups C and D (P>0.05). Conclusion Loading naringin composite scaffolds have good biocompatibility and effect in repair of rabbit articular osteochondral defects.
The purpose of this study is to investigate the effect of superparamagnetic chitosan FGF-2 gelatin microspheres (SPCFGM) on the proliferation and differentiation of mouse mesenchymal stem cells. The superparamagnetic iron oxide chitosan nanoparticles (SPIOCNs) were synthesized by means of chemical co-precipitation, combined with FGF-2. Then The SPCFGM and superparamagnetic chitosan gelatin microspheres (SPCGM) were prepared by means of crosslinking-emulsion. The properties of SPCFGM and SPIONs were measured by laser diffraction particle size analyser and transmisson electron microscopy. The SPCFGM were measured for drug loading capacity, encapsulation efficiency and release pharmaceutical properties in vitro. The C3H10 cells were grouped according to the different ingredients being added to the culture medium: SPCFGM group, SPCGM group and DMEM as control group. Cell apoptosis was analyzed by DAPI staining. The protein expression level of FGF-2 was determined by Western blot. The proliferation activity and cell cycle phase of C3H10 were examined by CCK8 and flow cytometry. The results demonstrated that both of the SPIOCNs and SPCFGM were exhibited structure of spherical crystallization with a diameter of (25±9) nm and (140±12) μm, respectively. There were no apoptosis cells in the three group cells. Both the protein expression level of FGF-2 and cell proliferation activity increased significantly in the SPCFGM group cells(P<0.05). The SPCFGM is successfully constructed and it can controlled-release FGF-2, remained the biological activity of FGF-2, which can promote proliferation activity of C3H10 cells, and are non-toxic to the cell.
Objective To investigate the effects of in-vitro monolayer culture and three-dimensional (3-D) alginate microsphere culture on the differentiation of normal human nucleus pulposus cells (NPCs), and to discuss the regulatory mechanism of restoring the phenotype of dedifferentiated NPCs by culturing resveratrol (RES) in 3-D alginate microsphere. Methods Normal human nucleus pulposus tissues were harvested for culture and identification of NPCs from 6 patients with burst lumbar vertebra fracture. NPCs at passages 1, 3, 5, and 7 in the in-vitro monolayer culture were harvested to observe the morphology, cell aging, and proteoglycan expression. The cell proliferation rates of NPCs at passage 1 in-vitro in monolayer culture and in 3-D alginate microsphere culture were detected. NPCs at passage 7 were randomly divided into 3-D alginate microsphere control group (group A), RES group (group B), silent mating type information regulation 2 homolog 1 (SIRT1)- small interfering RNA (siRNA) + RES group (group C), and negative control-siRNA + RES group (group D); and NPCs in the in-vitro monolayer culture was monolayer control group (group E). After corresponding treatment, Western blot was used for determining the protein expressions of SIRT1, Aggrecan, and collagen type II; real-time fluorescence quantitative PCR was used for detecting SIRT1 mRNA expression. Results The cultured cells were identified to be NPCs. Morphological observation, senescence-associated β-galactosidase (SA-β-gal) staining, and toluidine blue staining showed that dedifferentiation of normal NPCs tended to occur under continuous in-vitro monolayer culture, which was more obvious with increase of passage number. NPCs in 3-D alginate microsphere culture showed significantly lower proliferation rate than NPCs in the in-vitro monolayer culture (P lt; 0.05), but it could significantly improve the protein expressions of collagen type II and Aggrecan in dedifferentiated NPCs, showing significantly difference between groups E and A (P lt; 0.05). The protein expressions of SIRT1, collagen type II, and Aggrecan in group B were significantly improved when compared with that in group A (P lt; 0.05). Real-time fluorescence quantitative PCR and Western blot showed that the expressions of SIRT1 mRNA and proteins in group C were significantly inhibited after transfected with SIRT1-siRNA when compared with those in groups B and D (P lt; 0.05), and the protein expressions of collagen type II and Aggrecan in group C were significantly lower than those in groups B and D (P lt; 0.05). Conclusion Continuous in-vitro monolayer culture could efficiently cultivate numerous seeding NPCs, but it is liable to dedifferentiate. In 3-D alginate microsphere culture, RES could restore the phenotype of dedifferentiated NPCs and synthesize more extracellular matrix, which is related to the regulation of SIRT1.
There are six important developmental milestones for yttrium 90 microspheres in treatment of hepatocellular carcinoma (HCC). These milestones are: ① development of concepts in treatment of HCC; ② development of concepts in internal radiation therapy; ③ from basic, translational and clinical researches to clinical application; ④ internationally recognized indications for palliative treat ment of HCC; ⑤ from palliative to curative treatment of HCC after tumor downstaging with yttrium 90 microspheres using liver resection or liver transplantation; ⑥ non-surgical treatments using yttrium 90 microsphere as curative treatments. The developmental stages of yttrium 90 microsphere in treatment of HCC have undergone a very prolonged period and these stages will continue to evolve. As HCC is prevalent in China, permission of the State Food and Drug Administration to allow yttrium 90 microsphere to be clinically used on HCC patients in China will benefit a lot of patients who were not treatable by other means.
Curcumin-loaded poly (α-isobutyl cyanoacrylate) microspheres (Cur-HP-β-CD-PiBCA) were prepared by one-step emulsification with α-isobutyl cyanoacrylate as materials, poloxamer 188 as emulsifier, and curcumin complex with hydroxypropyl-β-cyclodextrin (Cur-HP-β-CD) as drug prepared by kneading method. Effects of emulsifier and drug concentration on microspheres size and distribution, drug loading and encapsulation efficiency were investigated in detail. And the curcumin release of drug-loaded microspheres was also studied. Results showed that as the emulsifier concentration increased from 0.01% to 0.07%, particle size of the drug-loaded microspheres decreased while particle size distribution, drug loading and entrapment efficiency increased. The optimized concentration of surfactant was 0.05%. With increasing the concentration of drug from 0.03% to 0.07%, drug loading of Cur-HP-β-CD-PiBCA increased, but encapsulation efficiency decreased. Additionally, the results of drug release experiments revealed that the higher drug loading of Cur-HP-β-CD-PiBCA was, the lower cumulative release percentage was. Drug-loading of cumulative inclusions in HP-β-CD by PiBCA can improve its wettability, and increase the degree of dissolution and bioavailability.
Objective To review the research progress of growth factor sustained-release microspheres in fat transplantation. Methods The recently published 1iterature at home and abroad related the growth factor sustained-release microspheres in fat transplantation was reviewed and analyzed. Results The sustained-release microsphere carrier materials include natural polymer materials and synthetic polymer materials.The sustained-release complexes of different microsphere materials with different growth factors can promote the vascularization of transplanted fat in a timely manner, improve the survival rate of grafts, and reduce the incidence of complications such as liquefaction, calcification, and necrosis. Conclusion The growth factor sustained-release microspheres have the characteristics of persistence and controllability, which is a research hotspot in the field of fat transplantation and has broad application prospects.
Four pigs underwent the hepatic arterial infusion with 32P glass microsphere (32PGM) and pigs were killed in 15th, 30th and 90th days separately. Pathological study showed that in early stage there were many small necrotic areas scattered along the hepatic arterioles. Three months later, these necrosis were gradually absorbed and replaced by regenerating hepatic cells. Tumor-inhibition experiment was performed in 40 Bal B/C mice bearing H22 hepatoma. Intratumoral injection of 0.2ml of 32PGM/glycerine suspension (group A, n=20) or 0.2ml of blank glass microsphere/glycerine suspension (group B, n=20) were performed. The average survival time in group A and group B was 24.8 and 11.8 days respectively. Five mice in group A were alive beyond 40 days after treatment, disappearance of tumor was found in two of them. This experiment demonstrates that 32PGM is effective for treatment of experiment hepatoma. The damage to hepatic tissue after infusion is associated with the irregular distribution of microsphere, and this lesion can completely recover within three months.
Objective To investigate the growth of tumors and the natural life length of the rats after the adriamycinethylcellulose microspheres(ADM-EC mc) were injected in the rats bearing transplantable liver cancer through their hepatic arteries.Methods ADM-EC mc were infused into the proper hepatic arteries of the Wistar rats (W256). All of the rats were divided randomly into five groups, group 1: control, group 2: normal saline, group 3: conventional ADM, group 4: placebo ethylcellulose microspheres, and group 5: ADM-EC mc. Results As compared with other four groups, the ADM-EC mc (group 5) showed the best inhibition of the growth of tumors and the longest mean life length of the rats. Conclusion Hepatic arterial infusion of ADM-EC mc can inhibit the growth of the tumor, aggravate the necrosis, and improve the effects of the chemotherapy of liver cancer.
Objective To evaluate the effect of the local del ivery of basic fibroblast growth factor 2 (bFGF-2) on the osseointegration around titanium implant of diabetic rats. Methods The bFGF-2-loaded poly (lactic-co-glycol ic acid) microspheres were prepared by water/oil/water (W/O/W) double-emulsion solvent evaporation method. Thirty-five male SPF level Sprague Dawley rats, weighing 220-250 g and aged 9 weeks, were selected as experimental animals. Ten rats were fedwith the routine diet as normal control group. The other 25 rats were made the diabetic animal model by giving high fat-sugar diet and a low dose streptozotocin (30 mg/ kg) intravenously; 20 rats were made the diabetic animal model successfully. Then 20 rats were randomly divided into diabetic control group (n=10) and bFGF-2 intervention group (n=10). A hole was drilled in the right tibia bone of all rats, and the titanium implant treated by micro-arc oxidation surface was planted into the hole. Simultaneously, the previously prepared microspheres and blood were mixed and were loaded on the surface of the implant before it was implanted into the rats of the bFGF-2 intervention group. At 4 and 8 weeks, the tibia containing implants was harvested, embedded with resin and made undecalcified tissue sl ices to compare the osseointegration. Results At 4 weeks, the implants of the normal control group were surrounded by new lamellar bone with continuity; whereas the tissue around the implants of the diabetic control group contained l ittle woven bone and some fibrous tissue; and obvious new formed bone with continuity was observed in bFGF-2 intervention group. At 8 weeks, the results of 3 groups were similar to those at 4 weeks. At 4 weeks, the percentage of bone-implant contact (BIC) in diabetic control group was significantly less than those in normal control group (P lt; 0.05) and in bFGF-2 intervention group (P lt; 0.05); the BIC in bFGF-2 intervention group was less than in normal control group, but showing no significant difference (P gt; 0.05). After 8 weeks, the BIC in normal control group and in bFGF-2 intervention group were significantly greater than that in diabetic control group (P lt; 0.05), but there was no significant difference between bFGF-2 intervention group and normal control group (P gt; 0.05). Conclusion Local del ivery of bFGF-2 around titanium implants may improve the osseointegration in diabetic rats.