Osteoarthritis (OA) is a common and complex inflammatory disorder that is frequently compounded by cartilage degradation, synovial inflammation, and osteophyte formation. Damaged chondrocytes release multiple danger mediators that exacerbate synovial inflammation and accelerate the progression to OA. Conventional treatments targeting only a single mediator of OA have failed to achieve a strong therapeutic effect. Addressing the crucial role of multiple danger mediators in OA progression, we prepared polyethylenimine (PEI)-functionalized diselenide-bridged mesoporous silica nanoparticles (MSN-PEI) with cell-free DNA (cfDNA)-binding and anti-oxidative properties. In models of surgery-induced and collagenase-induced arthritis, we showed that these cationic nanoparticles attenuated cartilage degradation and provided strong chondroprotection against joint damage. Mechanistically, multiple target blockades alleviated oxidative stress and dampened cfDNA-induced inflammation by suppressing the M1 polarization of macrophages. This study suggests a beneficial direction for targeting multiple danger mediators in the treatment of intractable arthritis.

Periodontitis is a common type of inflammatory bone loss and a risk factor for systemic diseases. The pathogenesis of periodontitis involves inflammatory dysregulation, which represents a target for new therapeutic strategies to treat periodontitis. After establishing the correlation of cell-free DNA (cfDNA) level with periodontitis in patient samples, we test the hypothesis that the cfDNA-scavenging approach will benefit periodontitis treatment. We create a nanoparticulate cfDNA scavenger specific for periodontitis by coating selenium-doped hydroxyapatite nanoparticles (SeHANs) with cationic polyamidoamine dendrimers (PAMAM-G3), namely G3@SeHANs, and compare the activities of G3@SeHANs with those of soluble PAMAM-G3 polymer. Both G3@SeHANs and PAMAM-G3 inhibit periodontitis-related proinflammation in vitro by scavenging cfDNA and alleviate inflammatory bone loss in a mouse model of ligature-induced periodontitis. G3@SeHANs also regulate the mononuclear phagocyte system in a periodontitis environment, promoting the M2 over the M1 macrophage phenotype. G3@SeHANs show greater therapeutic effects than PAMAM-G3 in reducing proinflammation and alveolar bone loss in vivo. Our findings demonstrate the importance of cfDNA in periodontitis and the potential for using hydroxyapatite-based nanoparticulate cfDNA scavengers to ameliorate periodontitis.

As a surging public health crisis, obesity and overweight predispose individuals to various severe comorbidities contributed by the accompanying chronic inflammation. However, few options exist for tackling chronic inflammation in obesity or inhibiting depot-specific adiposity. Here, we report that polycationic polyamidoamine (PAMAM) treatment can improve both aspects of obesity. With the discovery that the plasma cell-free RNA (cfRNA) level is elevated in obese subjects, we applied the cationic PAMAM generation 3 (P-G3) scavenger to treat diet-induced obese (DIO) mice. Intraperitoneal delivery of P-G3 alleviated the chronic inflammation in DIO mice and reduced their body weight, resulting in improved metabolic functions. To further enhance the applicability of P-G3, we complexed P-G3 with human serum albumin (HSA) to attain a sustained release, which showed consistent benefits in treating DIO mice. Local injection of HSA-PG3 into subcutaneous fat completely restricted the distribution of the complex within the targeted depot and reduced focal adiposity. Our study illuminates a promising cationic strategy to ameliorate chronic inflammation in obesity and target local adiposity.

Obesity is a pandemic health problem with poor solutions, especially for targeted treatment. Here we develop a polycation-based nanomedicine polyamidoamine generation 3 (P-G3) that-when delivered intraperitoneally-selectively targets visceral fat due to its high charge density. Moreover, P-G3 treatment of obese mice inhibits visceral adiposity, increases energy expenditure, prevents obesity and alleviates the associated metabolic dysfunctions. In vitro adipogenesis models and single-cell RNA sequencing revealed that P-G3 uncouples adipocyte lipid synthesis and storage from adipocyte development to create adipocytes that possess normal functions but are deficient in hypertrophic growth, at least through synergistically modulating nutrient-sensing signalling pathways. The visceral fat distribution of P-G3 is enhanced by modifying P-G3 with cholesterol to form lipophilic nanoparticles, which is effective in treating obesity. Our study highlights a strategy to target visceral adiposity and suggests that cationic nanomaterials could be exploited for treating metabolic diseases.

Periodontitis is a common type of inflammatory bone loss and is a risk factor for systemic diseases. The pathogenesis of periodontitis relies on inflammatory dysregulation, which represents a target for new therapeutic strategies to treat periodontitis. Here we demonstrate that cell-free DNA (cfDNA) is correlated with periodontitis in patient samples, and that cfDNA/TLR9 interactions participate in the immune response of periodontitis. We then tested the hypothesis that removing cfDNA would benefit periodontitis treatment. To create nucleic acid-binding nanoparticles (NABNs) specific for periodontitis, we coated bone-mimicking selenium-doped hydroxyapatite nanoparticles with cationic polyamidoamine dendrimers (PAMAM-G3), and compared the activities of these NABNs with those of soluble PAMAM-G3 polymers. Both NABNs and PAMAM-G3 inhibited periodontitis-related inflammation in vitro by scavenging cfDNA, and alleviated inflammatory bone loss in a mouse model of ligature-induced periodontitis. Both cfDNA scavengers also regulated the mononuclear phagocyte system in a periodontitis environment, promoting the M1 over the M2 macrophage phenotype. However, NABNs showed greater therapeutic effects than PAMAM-G3 in terms of scavenging and reducing inflammation and bone loss in vivo . Our findings demonstrate the importance of cfDNA in periodontitis and the potential for using cfDNA-scavenging and hydroxyapatite-based NABNs to ameliorate inflammation and bone loss in periodontitis.

Bone healing is regulated by multiple microenvironmental signals provided by the extracellular matrix (ECM). This study aimed to mimic the native osteoinductive microenvironment by developing an ECM using gene-transduced cells. The LIM mineralization protein-1 (LMP-1) gene was transferred to murine pre-osteoblast cells (MC3T3-E1) using lentiviral vectors. Western blotting assay indicated that the MC3T3-E1 cells expressed an increased level of bone morphologic protein-2, -4 and -7 (BMP-2, -4 and -7) after LMP-1 gene transduction. The transduced cells were then seeded into calcined bovine bone scaffolds and cultured for 7, 14, and 21 days to construct ECMs on the scaffolds. The ECM-scaffold composites were then decellularized using the freeze-drying method. Scaffolds without ECM deposition were used as controls. The composites and controls were implanted into critical-sized bone defects created in the distal femurs of New Zealand rabbits. Twelve weeks after the surgery, both microcomputed tomography and histologic results indicated that the 7-day-cell-modified ECM-scaffold composites induced bone regeneration with significantly larger volume, trabecular thickness and connectivity than the controls. However, the 14- and 21-day-cell-modified ECM-scaffold composites triggered sustained inflammation response even at 12 weeks after the surgery and showed less bone ingrowth and integration than their 7-day-cell-modified counterparts. In conclusion, these results highlight the viable gene transfer techniques for manipulating cells in a constructed microenvironment of ECM for bone regeneration. However, the unresolved inflammation relating to the duration of ECM modification needs to be considered.

OBJECTIVE To observe the genes expression of hypoxia inducible factor lα (HIF-1α) and HIF- 2α by inducing chondrogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) so as to provide a fundamental basis for HIF involving in the mechanism of chondrogenesis. METHODS High density pellet of hBMSCs was obtained by centrifugation and cultured with H-DMEM medium containing 2% fetal bovine serum (control group) and with chondrogenic medium (chondrogenic induction group) under hypoxia (2% O2) for 3 weeks. Immunohistochemistry staining was utilized to identify extracellular proteoglycan and collagen type II at 3 weeks after culture. Western blot was applied for measuring HIF-1α and HIF-2α protein levels at 1 week after culture. Real-time quantitative PCR was performed to detect the genes expressions of HIF-1α, HIF-2α, Sox-9, collagen type II, collagen type X, and Aggrecan at 1, 2, and 3 weeks after culture. RESULTS Toluidine blue staining showed sparse nucleus in the control group, and dense nucleus in the chondrogenic induction group; extracellular matrix staining was deeper in the chondrogenic induction group than the control group. Immunohistochemical staining for collagen type II was positive in cytoplasm; when compared with the chondrogenic induction group, the control group showed sparse and light-coloured nucleus. At 1 week after culture, the protein expression levels of HIF-1α and HIF-2α in the chondrogenic induction group were significantly lower than those in the control group (t = 8.345, P = 0.001; t = 7.683, P = 0.002). When compared with control group, the HIF-1α mRNA expression was significantly down-regulated at 1 week and significantly up-regulated at 2 weeks in chondrogenic induction group (P < 0.05), but no significant difference was found at 3 weeks between the 2 groups (P > 0.05). And the mRNA expression of HIF-2α was significantly down-regulated and mRNA expression of Sox-9 was significantly up-regulated after chondrogenic differentiation when compared with the control group (P < 0.01). The mRNA expressions of collagen type II and collagen type X were significantly up-regulated at 2 and 3 weeks after chondrogenic differentiation when compared with the control group (P < 0.05). And the mRNA expression of Aggrecan was significantly up-regulated at each time point after chondrogenic differentiation (P < 0.05). CONCLUSION HIF-1α may involve the hBMSCs chondrogenic differentiation under hypoxia, while HIF-2α expression is depressed throughout the period and may have negative effect on differentiation.

The precise mechanism of bone regeneration in different bone graft substitutes has been well studied in recent researches. However, miRNAs regulation of the bone formation has been always mysterious. We developed the anterior lumbar interbody fusion (ALIF) model in pigs using equine bone protein extract (BPE), recombinant human bone morphogenetic protein-2 (rhBMP-2) on an absorbable collagen sponge (ACS), and autograft as bone graft substitute, respectively. The miRNA and gene expression profiles of different bone graft materials were examined using microarray technology and data analysis, including self-organizing maps, KEGG pathway and Biological process GO analyses. We then jointly analyzed miRNA and mRNA profiles of the bone fusion tissue at different time points respectively. Results showed that miRNAs, including let-7, miR-129, miR-21, miR-133, miR-140, miR-146, miR-184, and miR-224, were involved in the regulation of the immune and inflammation response, which provided suitable inflammatory microenvironment for bone formation. At late stage, several miRNAs directly regulate SMAD4, Estrogen receptor 1 and 5-hydroxytryptamine (serotonin) receptor 2C for bone formation. It can be concluded that miRNAs play important roles in balancing the inflammation and bone formation.

[目的]为研究患者来源干细胞成骨分化的差异性,选取临床诊断为骨质疏松症患者的骨髓干细胞进行成骨分化诱导.[方法]采用密度梯度离心法,从临床6名患者(骨质疏松症3人,非骨质疏松症3人)的腰椎骨髓血液中分离获得原代骨髓间充质干细胞,并体外扩增至3-4代后进行实验.成骨诱导液的成分包括地塞米松(100 nmoL/L),二磷酸抗坏血酸(0.05 mmoL/L),β-甘油磷酸钠(10 mmoL/L)溶解于含有100 mL/L胎牛血清的低糖DMEM中.通过测定hMSC的增值与碱性磷酸酶(ALP)含量反应干细胞成骨分化活性.定量PCR检测Runx-2、ALP及成骨标志基因osteocalcin (OC)和osteonectin(ON)表达水平;通过矿化结节茜素红染色确认并定量检测钙离子浓度.[结果]比较两组干细胞增殖差异,骨质疏松组较非骨质疏松组降低,而ALP含量无显著差异.Q-PCR检测显示在第3、7天时,骨质疏松组Runx-2、ALP的mRNA表达水平均显著低于非骨质疏松组.骨质疏松组的成骨相关基因OC在3、7、14d时mRNA表达水平均显著低于非骨质疏松组,而ON仅在第7天表达具有显著差异;矿化结节染色及钙离子定量检测显示,较之非骨质疏松组,骨质疏松组矿化结节染色浅,钙定量降低.[结论]使用成骨诱导干细胞分化方案(地塞米松、二磷酸抗坏血酸、β-甘油磷酸钠)结果提示骨质疏松症患者的干细胞成骨分化能力较非骨质疏松患者降低.因此,选取有骨质疏松症患者自身的骨髓间充质干细胞作为治疗的种子细胞可能并不适用于临床.

BACKGROUND: The molecular mechanism of periprosthesis osteolysis is not yet completely clear. Periprosthetic osteolysis and absorption is the pathological and physiological process typical of artificial joint loosening. Interleukin-1 can affect bone resorption process through a mitogen-activated protein kinases(MAPK) signaling pathway. OBJECTIVE: To explore the effects of siRNA-induced interleukin-1 receptor-associated kinase-4 gene(IRAK-4) silence on MAPK expression in MG63 cells, which may provide experimental basis for treatment and prevention of periprosthesis osteolysis. METHODS: The siRNA sequences of the target gene, IRAK-4, were constructed and transferred into MG63 cells using Lipofectamine 2000. There were three groups: blank group=MG63 cells, control group = MG63 cells transfected with scrambled IRAK-4siRNA, and silence group=MG63 cells transfected with specific IRAK-4 siRNA. The protein level of extracellular regulated kinase(ERK), c-Jun N-terminal kinase(JNK) and p38 mitogenactivated protein kinases(p38MAPK) were detected by western blot assay. RESULTS AND CONCLUSION: The expression of IRAK-4 mRNA and protein in the silence group was significantly decreased compared with the control group. Compared with the blank and control groups, 48 hours after the transfection, IRAK-4 gene silencing in MG63 cells decreased protein expression of p-JNK1/2P46, p-ERK1/2 and p-p38MAPK(P < 0.05). IRAK-4 silencing inhibited ERK, JNK and p38MAPK expression in osteoblast-like cells.

【Objective】 To explore the effects of siRNA-induced interleukin-1 receptor-associated kinase-4(IRAK-4) gene silence on apoptosis of MG63 cells and the expression levels of related genes Bcl-2 and Bax. 【Methods】 The gene transfection(control group = MG63 cells; SC group = MG63 cells transfected with scrambled IRAK-4 siRNA; KD group = MG63 cells transfected with IRAK-4-specific siRNA) was performed using Lipofectamine 2000. The apoptosis of MG63 cells were tested by FCM and terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL) methods. The protein level of Bcl-2 and Bax were detected by Western blotting. 【Result】 The expression of IRAK-4 mRNA and protein in the KD group were significantly decreased compared with other two groups. Compared with the control groups, 48 hours after the transfection, IRAK-4 gene silencing in MG63 cells caused morphological changes, inhibited growth, increased apoptosis(P < 0.05) and decreased protein expression of Bcl-2 and the ratio of Bcl-2 / Bax(P <0.05). There was a significant correlation between the percentages of apoptotic MG63 cells and Bcl-2 / Bax protein expression(P =0.011). 【Conclusion】 The results indicated that IRAK-4 gene silencing in MG63 cells increase apoptosis, which may be related to the decreased Bcl-2 / Bax ratio.

Whether alendronate treatment has a residual effect on bone ingrowth into porous biomaterial in humans or experimental animals after treatment withdrawal is still unknown. The purpose of this study was to investigate bone ingrowth into porous tantalum and carbon fiber interbody implants after discontinuing alendronate treatment in experimental spinal fusion in pigs.Twenty-four pigs were randomly divided into two groups of each 12 pigs. The pigs underwent anterior intervertebral lumbar arthrodeses at L2-3, L4-5 and L6-7. Each level was randomly allocated to one of the three implants: a porous tantalum ring with pedicle screw fixation, a porous tantalum ring or a carbon fiber cage with anterior staple fixation. The central hole of implants was packed with an autograft. Alendronate was given orally for the first 3 months to one of the two groups. The pigs were observed for 6 months postoperatively. Histology and micro-CT scans were done at the endpoint.The spinal fusion rates of each implant showed no differences between two treatment groups. Furthermore, no differences were found between two groups as for bone ingrowth into the central holes of implants and bone-implant interface in each implant, or as for the pores of tantalum implants. Trabecular bone microarchitecture in the central hole of the carbon fiber cage did not differ between two treatment groups.The application of ALN, with a dose equivalent to that given to humans during the first 3 months after surgery, does not maintain a residual effect on spinal fusion with porous tantalum ring and autograft after treatment withdrawal in a porcine ALIF model.

Objective To screen the osteogenesis-specific miRNAs and forecasting target gene in human adipose-derived stem cells (ADSCs). Methods Three pairs of microRNAs of osteo-differentiated human ADSCs were collected. miRNAs were screened by microarray technique, and analysis with SAM and Cluster software. miRNAs were confirmed by qRT-PCR. Results Total nine different miRNAs were found, among which has-miR-17, has-miR-20a, has-miR-20b, has-miR-106a, and has-miR-199b-5p were up-regulated, while has-miR-125a-5p, has-miR-125b, has-miR-31, and has-miR-193a-3p were down-regulated. Conclusions There was differential miRNAs expression during ADSCs osteo-differentiation and some of the target genes were forcasted.

PURPOSE To evaluate disk degeneration in human and animal models by using a T1ρ magnetic resonance (MR) imaging technique to help in understanding the natural history and progression of intervertebral disk degeneration. MATERIALS AND METHODS After institutional review board approval was obtained, 80 subjects (54 men and 26 women; mean age ± standard deviation, 31.6 years ± 6.20) with 400 lumbar intervertebral disks were examined at MR imaging. With approval from the animal care committee, six rhesus monkeys received two levels of either annulus fibrosus puncture or pingyangmycin subendplate injection at L3-4 and L5-6 to mimic disk degeneration. Lumbar spines of all the animals were examined at radiography and MR imaging preoperatively and 1 day and 1, 3, 6, 9, and 13 months postoperatively. Pfirrmann grading system and T1ρ quantification were used to evaluate the degenerative degree of the disks of both humans and animals. RESULTS The mean T1ρ values of lumbar intervertebral disks of human subjects were 136.0 msec ± 31.4 and 76.1 msec ± 14.2 at Pfirrmann grades II and III, respectively. The T1ρ values in lumbar intervertebral disks of the rhesus monkey models of disk degeneration had a rapid decrease from approximately 110 msec to 80 msec and then tended to stabilize after operation. There was a large T1ρ value decrease between Pfirrmann grades II and III in human subjects that coincided with the rapid degeneration process of lumbar intervertebral disks in the rhesus monkeys. Pfirrmann grades were significantly correlated with T1ρ values in both humans (r = -0.681, P < .001) and rhesus monkeys (r = -0.824, P < .001). CONCLUSION The data demonstrate that rapid intervertebral disk degeneration occurs early in the degenerative cascade, between Pfirrmann grades II and III.

The aim of this study is to identify the effects of interleukin-1 receptor-associated kinase-4 (IRAK-4) gene silencing on human osteoblast-like cells. The siRNA sequences of the target gene, IRAK-4, were constructed and transferred into MG63 cells (control group = MG63 cells; SC group = MG63 cells transfected with scrambled IRAK-4 siRNA; KD group = MG63 cells transfected with 75 nM IRAK-4 siRNA). The morphological changes, cell growth, cell-cycle progression, apoptosis, and the expression of various cytokines and proteins were compared. Compared with the control and SC groups, IRAK-4 gene silencing in MG63 cells caused morphological changes, inhibited growth, altered the cell-cycle distribution, increased apoptosis (p < 0.05), decreased bone alkaline phosphatase and osteocalcin levels (p < 0.05), and decreased protein expression of Bcl-2/Bax and Bcl-2, p-JNK1/2, p-ERK1/2, and p-p38MAPK (p < 0.05). The results indicated that IRAK-4 gene silencing in MG63 cells inhibited cell proliferation and function and increase apoptosis, which may be related to the decreased Bcl-2/Bax ratio and inhibition of the protein expression of various components of the mitogen-activated protein kinase pathways. The results of this study may help improve the understanding of the relationship between IRAK-4 and osteoblast-like cells and the interactions between various cytokines in the periprosthetic inflammatory environment.

BACKGROUND: miRNAs have emerged as important regulators in various physiological and pathological processes of cell differentiation, and can regulate the osteogenic differentiation of adipose-derived stem cells. OBJECTIVE: To screen the osteogenesis-specific miRNAs, and analyze the expression pattern of these miRNAs in osteogenic differentiation of adipose-derived stem cells. METHODS: Adipose-derived stem cells were isolated and cultured from human subcutaneous fat. The osteogenesis-specific miRNAs were screened by gene microarray technique. The relative expression of these miRNAs was analyzed on 7, 14, and 21 days by RT-PCR. The osteogenesis-specific proteins were detected on 7, 14, and 21 days by enzyme linked immunosorbent assay kit. RESULTS AND CONCLUSION: {circled digit one}The 3 rd passage adipose-derived stem cells were homogeneous. Osteogenesis, adipogenesis, and chondrogenesis differentiation of adipose-derived stem cells need specific condition under an inverted microscope. {circled digit two}Nine osteogenesis-specific miRNAs were picked up by gene microarray technique, five were upregulated and four were downregulated. {circled digit three}On day 7 in osteogenic differentiation, miR-106a expression was upregulated 1.58 folds (P < 0.05). On day 14, nine miRNAs were upregulated. On day 21, five miRNAs were upregulated and four were downregulated. {circled digit four}The concentration of osteogenesis-specific proteins such as osteocalcin, alkaline phosphatase, collagen? and bone sialoprotein were increased on day 7, peaked on day 14 and slightly decreased on day 21.

Bone marrow-derived, circulating endothelial progenitor cells (EPCs) contribute to neovascularization in various diseases, and represent a very interesting alternative cell source for enhancing vasculogenesis in regenerative medicine. In this study, we investigated the effects of Ginkgolide B (GB) on proliferation and differentiation of EPCs, and the involved signaling pathway in vitro. EPC proliferation, migration, adhesion and angiogenesis activities were assessed with the WST-8 assay, Transwell chamber assay, cell counting and angiogenesis kit, respectively. Apoptosis was detected with annexin V and propidium iodide staining. The protein expression of angiogenesis-related makers was detected by Western blot, and related gene expression was determined by real-time polymerase chain reaction (RT-PCR). The results showed that GB promoted the proliferation and endothelial gene expression, and markedly enhanced vascular endothelial growth factor-induced migration response and the capability to incorporate into the vascular networks in EPCs. GB protected EPCs from H2O2-induced cell death. GB induced the phosphorylation of eNOS, Akt and p38, which in turn promoted cell proliferation and function. In conclusion, the present study demonstrates that GB, at a near medical applied dose, increases the number and functional activities of EPCs with involvement of Akt/endothelial nitric oxide synthase and mitogen-activated protein kinase (MAPK)/p38 signal pathways. These findings raise the intriguing possibility that GB may play an important role in the protection and revascularization of blood vessels.

Sinomenine (SN) is an alkaloid extracted from the medicinal plant, Sinomenium acutum which has been utilized to treat rheumatoid arthritis (RA) in China for centuries. Previous studies showed that SN had anti-inflammatory and anti-rheumatic effects. The aim of the present study was to investigate the effect of SN on interleukin-1beta (IL-1beta)-induced expression of major cartilage damaging proteases in human osteoarthritic chondrocytes. Human osteoarthritic chondrocytes were obtained from the knee of patients undergoing total knee arthroplasty surgery due to OA. Human osteoarthritic chondrocytes and SW1353 cells were plated in monolayer culture. Cell viability was evaluated using MTT assay. SN was added before stimulation with 10 ng/mL human recombinant IL-1beta. mRNA expression of MMPs was measured by RT-PCR. Protein expression was detected by Western blotting. SN suppressed IL-1beta-induced MMP-1, MMP-3, MMP-9, and MMP-13 mRNA and protein expression in SW1353 cells and human osteoarthritic chondrocytes. SN inhibited the catabolic effect of IL-1beta by interception of proteolytic enzymes expression. The cartilage catabolic proteases inhibitory ability and the well-known anti-inflammatory activity make SN a potentially novel therapeutic agent for OA.   Key words: Sinomenine, interleukin-1, osteoarthritis, chondrocytes, matrix metalloproteinases.

Objective To evaluate the feasibility of collagen complex gradient tricalcium phosphate composite scaffolds for cartilage tissue engineering by observing the compatibility and adhesion of chondrocytes. Methods High purified chondrocytes from knee joints of 8-week-old New Zealand rabbits were obtained by enzyme digestion, then the chondrocytes of the third generation were cultured combined with collagen complex gradient tricalcium phosphate composite scaffolds in vitro.Chondrocyte morphology, collagen Ⅱ expression, chondrogenesis, the compatibility of chondroeyte and scaffolds were evaluated with inverted microscope, HE staining, scanning electron microscope (SEM) and immunohistochemistry.Results By SEM, the scaffold had regular, porous architecture of communicated microholes.The average pore diameter was 100-150 μm.Observation revealed good hydrophilicity of the composite scaffold.The chondrocytes adhered to the surface, proliferated and migrated into the inside of the scaffold.Chondrocytes attached to wall of microholes of the scaffold had largely maintained morphology and could secrete the extracellular matrix on the porous scaffold.Conclusions Collagen complex gradient tricalcium phosphate composite scaffold possesses good cellular compatibility.