PLLA Scaffolds Research Articles

PLLA scaffold modification using magnetron sputtering of the copper target to provide antibacterial properties

Abstract Using the electrospinning method, we produced biodegradable scaffolds from poly- l -lactide acid polymer (PLLA – poly- l -lactide acid). Using DC magnetron sputtering of the copper target we modified the surface of the scaffolds. For investigate scaffolds morphology, structure and elemental composition were used scanning electron microscopy, X-ray diffraction and X-ray fluorescence analysis. The results of scanning electron microscopy reveal that scaffolds consist of chaotically located fibres. The diameters of fibres range from 0.8 to 2 µm. Initially amorphous scaffold after modification has crystalline structure. The count of oxygen and copper with modification is increased, but count of carbon decreased. For the investigation of the scaffolds wetting ability were used glycerol and water. The wetting angles for the both liquids were similarly comparable. The values for the wetting angles range from 114 ± 5° to 125 ± 5°, what indicated that scaffolds had hydrophobic properties. Testing for antibacterial features indicated that the modified scaffolds are capable to have a bacteriostatic effect. Compared to the number of bacteria cultured without scaffold (11.8 ± 1.26 CFU × 104/ml), two modified samples have bacteriostatic properties (reducing the number of bacteria on 30 and 50%). Economically effective method PLLA scaffolds modification could be used for creating low-cost wound dressings with antibacterial properties.

Characterization of PLLA scaffolds for biomedical applications

ABSTRACTThe porosity and pore size distribution of three-dimensional scaffolds have direct implications on their biomedical applications (tissue engineering, drug delivery, and wound dressing). Accordingly, in this paper, a fast, facile, and conservative method relying on low-field nuclear magnetic resonance (LF-NMR) for the evaluation of mean pore size and pore size distribution of polymeric scaffolds is reported. The applicability of the technique is demonstrated on poly-L-lactic acid scaffolds fabricated using the thermal induced phase separation. Results obtained through LF-NMR are successfully compared to scanning electron microscope and X-ray microcomputed tomography micrographs.

Abstract P29: Self Contained Bioreactor For Bone Regeneration

PURPOSE: The current gold standard for the repair of segmental bone defects is autologous bone grafts or flaps, however these are limited by donor site morbidity, limited graft tissue availability, and potential for complications at the harvest site. ASCs (adipose derived stem cells) have potential to aid bone regeneration due to their ability to differentiate into osteoblasts. BMP-2 (bone morphogenetic protein) has been shown to induce osteogenic differentiation of ASCs and enhance bone growth. We present a bioreactor for bone regeneration consisting of three main components: (i) a biodegradable PLLA scaffold seeded with ASCs, (ii) a drug reservoir made of PLLA and (iii) a controlled drug diffusion system for sustained release of BMP-2 to repair segmental bone defects. The drug reservoir is attached to the porous polymer scaffold seeded with ASCs and is capable of delivering growth factors for prolonged periods. METHODS: The components for the drug delivering setup were made from poly-lactic-acid (Purac Biomaterials) using solvent casting method. The device consists of two concentric tubes and a reservoir in between the tubes that stores BMP-2. Six 180 μm diffusion holes were drilled into the inner tube by pulsing a laser cutter. In vitro release tests were performed over a 30-day period. The concentration of BMP-2 released from devices was determined with an enzyme linked immunosorbent assay (R&D systems). The PLLA scaffolds were manufactured by a salt leaching method. ASC seeded scaffolds were inserted in the inner tube. We first evaluated the dosage(s) of BMP-2 that allows for the differentiation of ASCs into osteogenic cells using RT-PCR. ASC seeded devices were then loaded with BMP-2 and in vitro osteogenic differentiation of the ASCs was evaluated by direct delivery of BMP-2 from the drug reservoir to the seeded scaffold. RESULTS: The RT-PCR data showed increased expression of osteogenic markers such as ALK and Runx-2 in ASCs treated with 100ng/ml BMP-2 compared to no BMP-2 (p<0.05). Alizarin Red staining results showed that we were able to achieve osteogenic differentiation of ASCs with 100ng/ml BMP-2/day and the percentage of mineralization was greater in the PLLA scaffold compared to ‘no scaffold’ (p<0.05). The results for drug release kinetics showed that the drug delivery setup test was effective in achieving controlled local release of BMP-2 for 30 days. The results of the sealed (no hole) devices (n=2) validated sealing techniques for the drug-release reservoirs. The diffusion tests (n=6) indicated that 6x180 μm holes allowed for a sustainable and controlled BMP-2 release in the range of 50–100 ng/ml/day for 30 days. CONCLUSION: The bone bioreactor was able to release BMP-2 for 30 days in a controlled manner. The ASC seeded PLLA scaffold exposed to 50-100ng/m/day of BMP-2 produced significantly higher mineralization as compared to no scaffold. Further in vivo testing will be done to demonstrate that directly delivering BMP-2 from our reservoir to the ASC seeded scaffold enhances bone regeneration.

Sustained delivery of calcium and orthophosphate ions from amorphous calcium phosphate and poly(L-lactic acid)-based electrospinning nanofibrous scaffold

The purpose of this study is to investigate electrospinning poly(L-lactic acid) (PLLA) nanofibrous scaffold with different contents of amorphous calcium phosphate (ACP), which is suitable for using in bone regeneration through sustained release of calcium and orthophosphate ions. Three groups of nanofibrous scaffolds, ACP-free PLLA, ACP-5 wt%/PLLA and ACP-10 wt%/PLLA, are developed and characterized by scanning electron microscopy and gel permeation chromatography. Calcium and phosphate colorimetric assay kits are used to test ions released from scaffold during hydrolytic degradation. The results show ACP-5 wt%/PLLA and ACP-10 wt%/PLLA scaffolds have relatively high degradation rates than ACP-free PLLA group. The bioactivity evaluation further reveals that ACP-5 wt%/PLLA scaffold presents more biocompatible feature with pre-osteoblast cells and significant osteogenesis ability of calvarial bone defect. Due to the facile preparation method, sustained calcium and orthophosphate release behavior, and excellent osteogenesis capacity, the presented ACP/PLLA nanofibrous scaffold has potential applications in bone tissue engineering.

Evaluation of procedures to quantify solvent retention in electrospun fibers and facilitate solvent removal

Electrospun fiber scaffolds crafted from polyesters are studied extensively for potential tissue engineering applications. For translation of electrospun fibers into the clinic, the FDA requires analysis and quantification of any organic solvent that may be retained in the fibers since many organic solvents can negatively affect cells and tissues. If a significant amount of solvent is retained, then developing procedures for efficient solvent removal may enhance the clinical potential of these materials. In this study we use fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and nuclear magnetic resonance spectroscopy (NMR) to analyze solvent retention. A correlative analysis shows that both FTIR and TGA accurately predicted retention of two different solvents (HFP and chloroform) in our electrospun PLLA scaffolds, thus validating these procedures. We also assess the efficacy of various fiber treatment methods to facilitate organic solvent removal and conclude that submersion in 70 % ethanol and heat treatment at 100 °C were the most efficient methods of removing solvent from electrospun PLLA fibers.

Investigation of silk fibroin nanoparticle-decorated poly(l-lactic acid) composite scaffolds for osteoblast growth and differentiation.

Attempts to reflect the physiology of organs is quite an intricacy during the tissue engineering process. An ideal scaffold and its surface topography can address and manipulate the cell behavior during the regeneration of targeted tissue, affecting the cell growth and differentiation significantly. Herein, silk fibroin (SF) nanoparticles were incorporated into poly(l-lactic acid) (PLLA) to prepare composite scaffolds via phase-inversion technique using supercritical carbon dioxide (SC-CO2). The SF nanoparticle core increased the surface roughness and hydrophilicity of the PLLA scaffolds, leading to a high affinity for albumin attachment. The in vitro cytotoxicity test of SF/PLLA scaffolds in L929 mouse fibroblast cells indicated good biocompatibility. Then, the in vitro interplay between mouse preosteoblast cell (MC3T3-E1) and various topological structures and biochemical cues were evaluated. The cell adhesion, proliferation, osteogenic differentiation and their relationship with the structures as well as SF content were explored. The SF/PLLA weight ratio (2:8) significantly affected the MC3T3-E1 cells by improving the expression of key players in the regulation of bone formation, ie, alkaline phosphatase (ALP), osteocalcin (OC) and collagen 1 (COL-1). These results suggest not only the importance of surface topography and biochemical cues but also the potential of applying SF/PLLA composite scaffolds as biomaterials in bone tissue engineering.

Tuneable hydrolytic degradation of poly(l-lactide) scaffolds triggered by ZnO nanoparticles

In this work we fabricate porous PLLA and PLLA/ZnO scaffolds with porosities ranging from 10 to 90% and average pore diameter of 125–250μm by solvent casting/particulate leaching method. The structural evolution of PLLA/ZnO scaffolds during their in vitro degradation in phosphate buffered saline (PBS) at physiological pH (7.4) has been studied as a function of porosity and obtained results were compared to plain PLLA scaffolds. The changes induced upon the hydrolytic degradation of scaffolds have been explored by measuring the pH changes of the medium, the mass loss, thermal transitions, crystalline structure, thermal stability and the morphological changes. It is shown that the degradation profile of scaffolds could be successfully modified by tuning both the amount of ZnO nanoparticles and by varying the scaffold porosity. Results reveal that the water dissociated on ZnO nanoparticle surfaces initiate hydrolytic degradation reactions by reducing the strength of the chemical bonds of the adjacent PLLA chains, causing them to further divide into water-soluble oligomers. Obtained results may be useful towards the development of antibacterial porous structures with tuneable degradation rates to be used as a substrate for the growth of different kind of cells and tissues.

Human auricular chondrocytes with high proliferation rate show high production of cartilage matrix.

Cartilage has a poor capacity for healing due to its avascular nature. Therefore, cartilage regenerative medicine including autologous chondrocyte implantation (ACI) could be a promising approach. Previous research has proposed various methods to enrich the cultured chondrocytes for ACI, yet it has been difficult to regenerate homogeneous native-like cartilage in vivo. The cell populations with an increased ability to produce cartilage matrix can show somatic stem cells-like characteristics. Stem cells, especially somatic stem cells are able to grow rapidly in vitro yet the growth rate is drastically reduced when placed in in vivo conditions [14]. Thus, in this study we investigated whether proliferation rate has an impact on in vivo regeneration of cartilage constructs by sorting human chondrocytes. The human chondrocytes were fluorescently labeled with CFSE and then cultured in vitro; once analyzed, the histogram showed a widening of fluorescence level, indicating that the cells with various division rates were included in the cell population. To compare the characteristics of the cell groups with different division rates, the chondrocytes were sorted into groups according to the fluorescence intensity (30 or 45 percent of cells plotted in the left and right sides of histogram). Then the cells of the rapid cell group and slow cell group were seeded into PLLA scaffolds respectively, and were transplanted into nude mice. Metachromatic regions stained with toluidine blue were larger in the rapid cell group compared to the slow cell group, indicating that the former had higher chondrogenic ability. We proposed a new method to enrich cell population with high matrix production, using proliferation rate alone.

Implantation of a Poly-l-Lactide GCSF-Functionalized Scaffold in a Model of Chronic Myocardial Infarction

A previously developed poly-l-lactide scaffold releasing granulocyte colony-stimulating factor (PLLA/GCSF) was tested in a rabbit chronic model of myocardial infarction (MI) as a ventricular patch. Control groups were constituted by healthy, chronic MI and nonfunctionalized PLLA scaffold. PLLA-based electrospun scaffold efficiently integrated into a chronic infarcted myocardium. Functionalization of the biopolymer with GCSF led to increased fibroblast-like vimentin-positive cellular colonization and reduced inflammatory cell infiltration within the micrometric fiber mesh in comparison to nonfunctionalized scaffold; PLLA/GCSF polymer induced an angiogenetic process with a statistically significant increase in the number of neovessels compared to the nonfunctionalized scaffold; PLLA/GCSF implanted at the infarcted zone induced a reorganization of the ECM architecture leading to connective tissue deposition and scar remodeling. These findings were coupled with a reduction in end-systolic and end-diastolic volumes, indicating a preventive effect of the scaffold on ventricular dilation, and an improvement in cardiac performance.

Sequential controlled-released dual-drug loaded scaffold for guided bone regeneration in a rat fenestration defect model.

A microbially-induced inflammatory periodontal disease is the main initiator to disrupt the periodontium. It is desirable to develop a newly guided bone regeneration (GBR) scaffold to accomplish the periodontal tissue regeneration for the concurrent control of inflammation. A novel therapeutic solution for GBR based on 3D multifunctional scaffolds, which combines the merits of osseous regeneration and local anti-inflammatory drug delivery, has been developed. The 3D dual-drug delivery scaffold (DDDS) loaded with parthenolide and naringin was successfully developed by thermally-induced phase separation techniques. The DDDS was hierarchically interconnected to the porous PLLA scaffold loaded with the hydrophobic parthenolide. In addition, the hydrophilic naringin loaded in chitosan microspheres was embedded in the scaffold. In vitro drug release profile results revealed that the DDDS showed an efficient sequential controlled release pattern with parthenolide delivered rapidly, followed by naringin delivered in a more sustained manner. Cell viability of MC3T3-E1 showed a combined effect of dual-drug delivery. Hemolysis of the DDDS was 1.84 ± 0.44%, which is less than that of the pure PLLA scaffold. To further evaluate the in vivo guided bone regeneration effect of the DDDS, a rat fenestration defect model was generated. The defects were harvested after 4 and 8 weeks for micro-CT and histological observation. The results suggested that the DDDS group had significantly increased the regenerated bone volume fraction compared to both the control and PLLA groups at 8 weeks, which was in parallel with the reduced expression of IL-6. This DDDS, as a GBR scaffold, might be utilized as a novel adjunctive treatment in periodontitis.

Effect of PEG addition on pore morphology and biocompatibility of PLLA scaffolds prepared by freeze drying

Purpose A 3wt% poly(L-lactic acid) (PLLA) with different concentrations of polyethylene glycol (PEG, 0~9wt%) was blended and lyophilized to evaluate the morphology and the biocompatibility of the PLLA/PEG scaffolds. The purpose of this study is to investigate the biocompatibility of the PLLA/ PEG blends. Morphology, degradation rate, cytotoxicity, skin sensitization, acute systemic toxicity, and intradermal reactivity are examined.

A space network structure constructed by tetraneedlelike ZnO whiskers supporting boron nitride nanosheets to enhance comprehensive properties of poly(L-lacti acid) scaffolds.

In this study, the mechanical strength and modulus of poly(L-lacti acid) (PLLA) scaffolds were enhanced with the mechanical properties of boron nitride nanosheets (BNNSs) and tetraneedlelike ZnO whiskers (T-ZnOw). The adhesion and proliferation of cells were improved as well as osteogenic differentiation of stem cells was increased. Their dispersion statues in PLLA matrix were improved through a space network structure constructed by three-dimensional T-ZnOw supporting two-dimensional BNNSs. The results showed that the compressive strength, modulus and Vickers hardness of the scaffolds with incorporation of 1 wt% BNNSs and 7 wt% T-ZnOw together were about 96.15%, 32.86% and 357.19% higher than that of the PLLA scaffolds, respectively. This might be due to the effect of the pull out and bridging of BNNSs and T-ZnOw as well as the crack deflection, facilitating the formation of effective stress transfer between the reinforcement phases and the matrix. Furthermore, incorporation of BNNSs and T-ZnOw together into PLLA scaffolds was beneficial for attachment and viability of MG-63 cells. More importantly, the scaffolds significantly increased proliferation and promoted osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The enhanced mechanical and biological properties provide the potentials of PLLA/BNNSs/T-ZnOw scaffolds for the application into bone tissue engineering.

Facile preparation of open-cellular porous poly (l-lactic acid) scaffold by supercritical carbon dioxide foaming for potential tissue engineering applications

Porous poly (l-lactic acid) (PLLA) scaffold has been widely used as substitutes for tissue engineering. However, PLLA is intrinsically difficult to be produced for low-density and high porosity by physical foaming procedure, due to its weak melt strength, slow crystallization kinetic, and low heterogeneous nucleation efficiency in bulk. For the sake of enhancing the PLLA’s crystallization and heterogeneous nucleation in supercritical CO2 (ScCO2) foaming, a pressure-induced flow (PIF) method was applied on neat PLLA. As a result, the PLLA’s crystallinity and its spherulite size increased from original 15.3% and 5.0nm to 42.1% and 28.5nm, respectively. High-strength and low-density PLLA foams with uniform and controlled cellular morphology were feasibly produced, varying the foaming temperature from 100 to 140°C in a ScCO2 batch foaming process. The closed cellular structure was transformed to high-interconnected porous structure, when reducing the foaming temperature. The open-cellular PLLA scaffolds foams, with a relatively high open pore content of 77.3%, prepared using this approach can achieve a high porosity up to 92.5%, and exhibit excellent compressive stress. To evaluate its tissue engineering application, long-term culture of mouse embryonic fibroblast cells (MEFs) demonstrated that the selected open-cellular PLLA scaffold provided prominent advantages ranging from enhanced cell adhesion and proliferation to facilitated nutrient transport. The combination of PIF and CO2 foaming process can produce a great promising PLLA scaffold for tissue engineering with desirable open-cellular structure, high-strength, low-cost and easy production capacity.

Negative Outcomes of Poly(l-Lactic Acid) Fiber-Reinforced Scaffolds in an Ovine Total Meniscus Replacement Model.

Our objective was to test the efficacy of collagen-hyaluronan scaffolds reinforced with poly(l-lactic acid) (PLLA) fibers in an ovine total meniscus replacement model. Scaffolds were implanted into 9 sheep (n = 1 at 8 weeks, n = 2 at 16 weeks, n = 3 at both 24, 32 weeks) following total medial meniscectomy. From 16 weeks on, explants were characterized by confined compression creep, histological, and biochemical analyses. Articular surfaces were observed macroscopically and damage was ranked histologically using the Mankin score. At sacrifice, three of the nine PLLA scaffolds had completely ruptured, and the intact scaffolds experienced progressive shape changes and severe narrowing in the body region at 16, 24, and 32 weeks. Aggregate compressive modulus and permeability did not improve with time. Histological and biochemical analyses showed significantly less extracellular matrix and less matrix organization compared to native tissue. Osteophytes, bone erosion, and cartilage damage were observed, increasing with time postimplantation. A buildup of lactic acid and/or the rapid loss of scaffold mechanical integrity due to PLLA degradation are probable causes for the joint abnormalities observed in this study. These results are in sharp contrast to those of our previous successful total meniscus replacement studies using polyarylate [p(DTD DD)] fiber-reinforced scaffolds. This suggests that PLLA fiber as produced in this study cannot be used as reinforcement for a meniscus replacement scaffold.

The effects of fiber diameter of electrospun PLLA scaffolds on annulus fibrous-derived stem cells

The effects of fiber diameter of electrospun PLLA scaffolds on annulus fibrous-derived stem cells

Modification and cytocompatibility of biocomposited porous PLLA/HA-microspheres scaffolds

Poly(L-lactic acid) and hydroxyapatie (PLLA/HA) composite scaffolds have good properties and suit to use as bone tissue engineering. In this work, hollow HA microspheres (HAM) with poor crystallinity were fabricated by a flame-drying method. The HAM has the potential to be used to release drugs or proteins in addition to improve osteoconductivity. Different ratios of PLLA/HAM were used to prepare porous composite scaffolds using the thermally induced phase separation technique. The HAMs were randomly incorporated into the PLLA porous scaffolds. As the HAMs ratio was increased, the porous composite scaffolds changed from ladder-like into isotropic structure. In addition, the compressive strength of PLLA/HAMs composite scaffolds improved first and declined with the increasing of HAMs ratio in the scaffolds. In vitro experiment showed that PLLA/HAMs composite scaffolds improved the attachment, migration, and differentiation of osteoblastic cells. These results demonstrated that the PLLA/HAMs composite scaffolds were superior to plain PLLA scaffold for bone tissue engineering.

Bone scaffolds loaded with siRNA-Semaphorin4d for the treatment of osteoporosis related bone defects.

Osteoporosis is a prominent disorder affecting over 200 million people worldwide. Recently, semaphorins have been implicated in the cell-cell communication between osteoclasts and osteoblasts and have been associated with the progression of osteoporosis. Previously, we demonstrated that knockdown of semaphorin4d (Sema4d) using siRNA delivered with a bone-targeting system prevented bone loss in an osteoporotic animal model. Here, we used this bone-specific technology containing siRNA-Sema4d and fabricated a PLLA scaffold capable of enhancing bone repair following fracture. We investigated the ability of the implant to release siRNA-Sema4d into the surrounding tissues over time and to influence new bone formation in a 3 mm femur osteoporotic defect model in ovariectomized rats. Delivery of the bone-targeting system released from PLLA scaffolds began 2 hours post-implantation, peaked at 1 day, and was sustained over a 21 day period. μCT analysis demonstrated a significantly higher bone volume/total volume bone mineral density and number of osteoblasts in the rats that were transplanted with scaffolds loaded with siRNA-Sema4d. These results confirm the specific role of Sema4d in bone remodeling and demonstrate that significant increases in the speed and quality of new bone formation occur when siRNA-Sema4d is delivered via a PLLA scaffold.

Composite poly(l-lactic-acid)/silk fibroin scaffold prepared by electrospinning promotes chondrogenesis for cartilage tissue engineering

Nanofibrous materials produced by electrospinning have attracted considerable attention from researchers in regenerative medicine. A combination of nanofibrous scaffold and chondrocytes is considered promising for repair of cartilage defect or damage. In the present study, we fabricated a poly(l-lactic-acid) (PLLA)/silk fibroin (SF) nanofibrous scaffold by electrospinning and evaluated its chondrogenic potential. The PLLA/SF nanofibers were characterized for diameter, surface wettability, swelling ratio, and tensile strength. Throughin vitroexperiments, PLLA/SF scaffold-chondrocyte interactions were investigated relative to the unmodified PLLA scaffold with regard to cellular adhesion, spreading, and proliferation by scanning electron microscopy and confocal laser scanning microscopy, and through analyses of DNA, sulfated glycosaminoglycan, and collagen. In addition, hematoxylin-eosin and Alcian blue-nuclear fast red staining were used to observe growth of chondrocytes, and secretion and distribution of cartilage-specific extracellular matrices in the scaffolds. Expressions of cartilage-related genes (collagen II, aggrecan, sox9, collagen I, and collagen X) were detected by real-time quantitative PCR. The PLLA/SF scaffold had better hydrophilicity, and could support chondrocytes adhesion and spreading more effectively than the unmodified PLLA scaffold. Chondrocytes secreted more cartilage-specific extracellular matrices and maintained their phenotype on the PLLA/SF scaffold. So it is concluded that the PLLA/SF scaffold is more conducive toin vitroformation of cartilage-like new tissues than the unmodified PLLA scaffold, and may be a promising material in cartilage tissue engineering.

Electrospun PLLA nanofiber scaffolds for bladder smooth muscle reconstruction.

Urinary bladder may encounter several pathologic conditions that could lead to loss of its function. Tissue engineering using electrospun PLLA scaffolds is a promising approach to reconstructing or replacing the problematic bladder. PLLA nanofibrous scaffolds were prepared utilizing single-nozzle electrospinning. The morphology and distribution of fiber diameters were investigated by scanning electron microscopy (SEM). Human bladder smooth muscle cells (hBSMCs) were isolated from biopsies and characterized by immunocytochemistry (ICC). Then, the cells were seeded on the PLLA nanofibers and Alamar Blue assay proved the biocompatibility of prepared scaffolds. Cell attachment on the nanofibers and also cell morphology over fibrous scaffolds were observed by SEM. The results indicated that electrospun PLLA scaffold provides proper conditions for hBSMCs to interact and attach efficiently to the fibers. Alamar Blue assay showed the compatibility of the obtained electrospun scaffolds with hBSMCs. Also, it was observed that the cells could achieve highly elongated morphology and their native aligned direction besides each other on the random electrospun scaffolds and in the absence of supporting aligned nanofibers. Electrospun PLLA scaffold efficiently supports the hBSMCs growth and alignment and also has proper cell compatibility. This scaffold would be promising in urinary bladder tissue engineering.

Fabrication and biocompatibility of poly(l-lactic acid) and chitosan composite scaffolds with hierarchical microstructures

The scaffold microstructure is crucial to reconstruct tissue normal functions. In this article, poly(l-lactic acid) and chitosan fiber (PLLA/CTSF) composite scaffolds with hierarchical microstructures both in fiber and pore sizes were successfully fabricated by combining thermal induced phase separation and salt leaching techniques. The composite scaffolds consisted of a nanofibrous PLLA matrix with diameter of 50–500nm, and chitosan fibers with diameter of about 20μm were homogenously distributed in the PLLA matrix as a microsized reinforcer. The composite scaffolds also had high porosity (>94%) and hierarchical pore size, which were consisted of both micropores (50nm–10μm) and macropores (50–300μm). By tailoring the microstructure and chemical composition, the mechanical property, pH buffer and protein adsorption capacity of the composite scaffold were improved significantly compared with those of PLLA scaffold. Cell culture results also revealed that the PLLA/CTSF composite scaffolds supported MG-63 osteoblast proliferation and penetration.