Physical Characteristics and Biocompatibility of 3D-Printed Polylactic-Co-Glycolic Acid Membranes Used for Guided Bone Regeneration.

Bioresorbable polymeric membranes for guided bone regeneration (GBR) were fabricated using the three-dimensional printing technique. Membranes made of polylactic-co-glycolic acid (PLGA), which consist of lactic acid (LA) and glycolic acid in ratios of 10:90 (group A) and 70:30 (group B), were compared. Their physical characteristics including architecture, surface wettability, mechanical properties, and degradability were compared in vitro, and their biocompatibilities were compared in vitro and in vivo. The results demonstrated that the membranes of group B had mechanical strength and could support the proliferation of fibroblasts and osteoblasts significantly better than those of group A (p < 0.05). The degradation rate in Group B was significantly lower than that in Group A, but they significantly produced less acidic environment (p < 0.05). In vivo, the membranes of group B were compared with the commercially available collagen membranes (group C). The amount of newly formed bone of rat's calvarial defects covered with the membranes of group C was stable after week 2, whereas that of group B increased over time. At week 8, the new bone volumes in group B were greater than those in group C (p > 0.05). In conclusion, the physical and biological properties of the PLGA membrane (LA:GA, 70:30) were suitable for GBR.

A Three-Dimensional Printed Polycaprolactone-Biphasic-Calcium-Phosphate Scaffold Combined with Adipose-Derived Stem Cells Cultured in Xenogeneic Serum-Free Media for the Treatment of Bone Defects.

The efficacy of a three-dimensional printed polycaprolactone-biphasic-calcium-phosphate scaffold (PCL-BCP TDP scaffold) seeded with adipose-derived stem cells (ADSCs), which were cultured in xenogeneic serum-free media (XSFM) to enhance bone formation, was assessed in vitro and in animal models. The ADSCs were isolated from the buccal fat tissue of six patients using enzymatic digestion and the plastic adherence method. The proliferation and osteogenic differentiation of the cells cultured in XSFM when seeded on the scaffolds were assessed and compared with those of cells cultured in a medium containing fetal bovine serum (FBS). The cell-scaffold constructs were cultured in XSFM and were implanted into calvarial defects in thirty-six Wistar rats to assess new bone regeneration. The proliferation and osteogenic differentiation of the cells in the XSFM medium were notably better than that of the cells in the FBS medium. However, the efficacy of the constructs in enhancing new bone formation in the calvarial defects of rats was not statistically different to that achieved using the scaffolds alone. In conclusion, the PCL-BCP TDP scaffolds were biocompatible and suitable for use as an osteoconductive framework. The XSFM medium could support the proliferation and differentiation of ADSCs in vitro. However, the cell-scaffold constructs had no benefit in the enhancement of new bone formation in animal models.

Bioactivity of a Novel Polycaprolactone-Hydroxyapatite Scaffold Used as a Carrier of Low Dose BMP-2: An In Vitro Study.

Scaffolds of polycaprolactone-30% hydroxyapatite (PCL-30% HA) were fabricated using melt stretching and multilayer deposition (MSMD), and the in vitro response of osteoblasts to the scaffolds was assessed. In group A, the scaffolds were immersed in 10 µg/mL bone morphogenetic protein-2 (BMP-2) solution prior to being seeded with osteoblasts, and they were cultured in the medium without BMP-2. In group B, the cell-scaffold constructs without BMP-2 were cultured in medium containing 10 µg/mL BMP-2. The results showed greater cell proliferation in group A. The upregulation of runt-related transcription factor 2 and osteocalcin genes correlated with the release of BMP-2 from the scaffolds. The PCL-30% HA MSMD scaffolds appear to be suitable for use as osteoconductive frameworks and BMP-2 carriers.

Effects of polycaprolactone-biphasic calcium phosphate scaffolds on enhancing growth and differentiation of osteoblasts.

BACKGROUND: Polycaprolactone (PCL)-biphasic calcium phosphate (BCP) scaffolds fabricated using Melt-Stretching and Compression Molding (MSCM) can release calcium and phosphate ions, which are essential for bone formation. OBJECTIVE: Responses of the osteoblasts seeded on three groups of scaffolds including group A; PCL-20% BCP (%wt), group B; PCL-30% BCP and group C (control); pure PCL (100% PCL) were evaluated. METHODS: The cell-scaffold constructs were made by seeding osteoblast cell lines at 1×105 cells/scaffold. The constructs of each group were divided for culturing in proliferation medium (PR) and osteogenic induction medium (OS) for 30 days. RESULTS: The cells attached and grew on the scaffolds of all groups. The cell number and the differentiation markers of groups A and B were remarkably higher than those of group C over the observation periods. Slow proliferation of the cells of group A and B in the PR medium in the first 7 days corresponded to the maximum increases in alkaline phosphatase activities (ALP). The maximum levels of ALP of those groups in the OS medium were not detected until day 14. The levels of osteocalcin of those groups were not statistically different when cultured in both mediums. CONCLUSIONS: The MSCM scaffolds are suitable for supporting attachment and growth of the osteoblasts. Additional BCP into the PCL-based scaffolds accelerate early differentiation of the cells in the constructs even without osteogenic-inductive condition.

In vivo biocompatibility and degradation of novel Polycaprolactone-Biphasic Calcium phosphate scaffolds used as a bone substitute.

BACKGROUND: Biocompatibility and degradation of poly ε-caprolactone (PCL)-Biphasic Calcium Phosphate (BCP) scaffolds fabricated by the "Melt Stretching and Compression Molding (MSCM)" technique were evaluated in rat models. OBJECTIVES: Degradation behaviors and histological biocompatibility of the PCL-20% BCP MSCM scaffolds and compare with those of PCL-20% ß-tricalcium phosphate (TCP) scaffolds commercially fabricated by Fused Deposition Modeling (FDM) were evaluated. METHODS: The study groups included Group A: PCL-20% BCP MSCM scaffolds and Group B: PCL-20% TCP FDM scaffolds, which were implanted subcutaneously in twelve male Wistar rats. On day 14, 30, 60 and 90, dimensional changes of the scaffolds and their surrounding histological features were assessed using Micro-Computed Tomography (µ-CT) and histological analysis. Changes of their molecular weight were assessed using Gel Permeation Chromatography (GPC). RESULTS: Formation of collagen and new blood vessels throughout the scaffolds of both groups increased with time with low degrees of inflammation. The µ-CT and GPC analysis demonstrated that the scaffolds of both groups degraded with time, but, their molecular weight slightly changed over the observation periods. All results of both groups were not significantly different. CONCLUSIONS: The PCL-20% BCP MSCM scaffolds were biocompatible and biodegradable in vivo. Their properties were comparable to those of the commercial PCL-20% TCP scaffolds.

Assessment of bone regeneration of a tissue-engineered bone complex using human dental pulp stem cells/poly(ε-caprolactone)-biphasic calcium phosphate scaffold constructs in rabbit calvarial defects.

The objective of the present study was to investigate the effect of a fabricated combination of poly-ɛ-caprolactone (PCL)-biphasic calcium phosphate (BCP) with the modified melt stretching and multilayer deposition (mMSMD) technique on human dental pulp stem cell (hDPSC) differentiation to be osteogenic like cells for bone regeneration of calvarial defects in rabbit models. hDPSCs extracted from human third molars were seeded onto mMSMD PCL-BCP scaffolds and the osteogenic gene expression was tested prior to implantation in vivo. Two standardized 11 mm in diameter circular calvarial defects were created in 18 adult male New Zealand white rabbits. The rabbits were divided into 4 groups: (1) hDPSCs seeded in mMSMD PCL-BCP scaffolds; (2) mMSMD PCL-BCP scaffolds alone, (3) empty defects and (4) autogenous bone (n = 3 site/time point/groups). After two, four and eight weeks after the operation, the specimens were harvested for micro-CT including histological and histomorphometric analysis. The explicit results presented an interesting view of the bioengineered constructs of hDPSCs in PCL-BCP scaffolds that increased the newly formed bone compared to the empty defect and scaffold alone groups. The results demonstrated that hDPSCs combined with mMSMD PCL-BCP scaffolds may be an augmentation material for bony defect.

Biological characteristic effects of human dental pulp stem cells on poly-ε-caprolactone-biphasic calcium phosphate fabricated scaffolds using modified melt stretching and multilayer deposition.

Craniofacial bone defects such as alveolar cleft affect the esthetics and functions that need bone reconstruction. The advanced techniques of biomaterials combined with stem cells have been a challenging role for maxillofacial surgeons and scientists. PCL-coated biphasic calcium phosphate (PCL-BCP) scaffolds were created with the modified melt stretching and multilayer deposition (mMSMD) technique and merged with human dental pulp stem cells (hDPSCs) to fulfill the component of tissue engineering for bone substitution. In the present study, the objective was to test the biocompatibility and biofunctionalities that included cell proliferation, cell viability, alkaline phosphatase activity, osteocalcin, alizarin red staining for mineralization, and histological analysis. The results showed that mMSMD PCL-BCP scaffolds were suitable for hDPSCs viability since the cells attached and spread onto the scaffold. Furthermore, the constructs of induced hDPSCs and scaffolds performed ALP activity and produced osteocalcin and mineralized nodules. The results indicated that mMSMD PCL-BCP scaffolds with hDPSCs showed promise in bone regeneration for treatment of osseous defects.

Physical characteristics and biocompatibility of the polycaprolactone-biphasic calcium phosphate scaffolds fabricated using the modified melt stretching and multilayer deposition.

Physical properties and biocompatibility of polycaprolactone (PCL)-biphasic calcium phosphate (BCP) scaffolds fabricated by the modified melt stretching and multilayer deposition (mMSMD) technique were evaluated in vitro. The PCL-BCP scaffold specimens included group A; PCL: BCP (wt%) = 80:20 and group B; 70:30. Mechanical properties of the scaffolds were assessed using a universal testing machine. Degradation behaviors of the scaffolds were assessed over 60 days. The amount of calcium and phosphate ions released from the scaffolds was detected over 30 days. Attachment and growth of osteoblasts on the scaffolds and indirect cytocompatibility to those cells were evaluated. The results showed that the scaffolds of both groups could withstand compressive forces on their superior aspect very well; however, their lateral aspect could only withstand light forces. Degradation of the scaffolds over 2 months was low (group A = 1.92 ± 0.47% and group B = 2.9 ± 1.3%,p > 0.05). The concentrations of calcium and phosphate ions released from the scaffolds of both groups significantly increased on day 7 (p < 0.05). Growth of the cells seemed to relate to accumulative increase in those ions. All results between the two ratios of the scaffolds were not statistically different.

Repairing calvarial defects with biodegradable polycaprolactone-chitosan scaffolds fabricated using the melt stretching and multilayer deposition technique.

The ability to repair bone defects of polycaprolactone-chitosan scaffolds containing 20% chitosan (PCL-20%CS) fabricated using the melt stretching and multilayer deposition (MSMD) technique was assessed and compared with commercial scaffolds. Two calvarium defects of 11 mm in diameter were created in each of the fifteen New Zealand white rabbits. The PCL-20%CS scaffolds were implanted in one site (group A) while another site was performed with PCL-tricalcium phosphate (TCP) scaffolds containing 20% TCP (PCL-20%TCP) fabricated by fused deposition modeling technique (FDM) (group B). At two, four and eight weeks thereafter, new bone regeneration within the defects was assessed using histomorphometric and micro-computed tomography (µ-CT) analysis. The result of histological sections demonstrated that chronic inflammatory reaction was generally detected along scaffolds of group A, but it was not found in group B. Over 8 weeks, the µ-CT analysis indicated that the average amount of new bone of group A was slightly less than that of group B (p>0.05). In conclusion, efficacy of the PCL-20%CS MSMD scaffolds for repairing bone defects was less than that of the PCL-20%TCP FDM scaffolds. However, MSMD scaffolding is still the technique of choice, but needed some modifications.

Biomechanical properties of novel biodegradable poly ε-caprolactone-chitosan scaffolds.

AIM: To investigate the biomechanical properties of poly ε-caprolactone (PCL)-chitosan (CS) scaffolds fabricated by the melt stretching and multilayer deposition technique. METHODS: The PCL-CS scaffolds containing CS at 0% (pure PCL), 10%, and 20% by weight were prepared. For the monolayer scaffolds, shear and blending tests simulating the reconstruction of orbital floor defects (situation A) and mandibular defects (situation B) were conducted. For the 3-D scaffolds, compression tests of their superior and lateral aspects were done. RESULTS: For the monolayer scaffolds, the pure PCL group had remarkably lower shear strength than the other groups (P > 0.05). In situation A, all groups withstood the forces without any significant difference. In situation B, the pure PCL group could withstand the forces remarkably lower than those of the other group (P < 0.05). The 3-D scaffolds of all groups could withstand compressive forces directed towards their superior aspects. However, they could not withstand the forces directed towards their lateral aspects at the limited strain. CONCLUSIONS: The monolayer scaffolds were suitable for reconstruction of the orbital floor and mandibular defects under light load-bearing conditions. The 3-D scaffolds could be used in the high load bearing-areas only if the forces were directed at their superior aspects.

Biodegradable polycaprolactone-chitosan three-dimensional scaffolds fabricated by melt stretching and multilayer deposition for bone tissue engineering: assessment of the physical properties and cellular response.

Fabrication of polycaprolactone (PCL)-chitosan (CS) three-dimensional (3D) scaffolds using the novel technique of melt stretching and multilayer deposition was introduced. In brief, firstly, the PCL-CS monofilaments containing 0% (pure PCL), 10%, 20% and 30% CS by weight were fabricated by melting and stretching processes. Secondly, the desired multilayer (3D) scaffolds were fabricated by arranging and depositing the filaments. Physical properties of the filaments and the scaffolds were evaluated. MC3T3-E1 cell lines were seeded on the scaffolds to assess their proliferation. A typical micro-groove pattern was found on the surfaces of pure PCL filaments due to stretching. The filaments of PCL-30%CS had the highest tendency of fracture during stretching and could not be used to form the scaffold. Increasing CS proportions tended to reduce the micro-groove pattern, surface roughness, tensile strength and elasticity of the filaments, whilst compressive strength of the PCL-CS scaffolds was not affected. The average pore size and porosity of the scaffolds were 536.90 ± 17.91 µm and 45.99 ± 2.8% respectively. Over 60 days, degradation of the scaffolds gradually increased (p > 0.05). The more CS containing scaffolds were found to increase in water uptake, but decrease in degradation rate. During the culture period, the growth of the cells in PCL-CS groups was significantly higher than in the pure PCL group (p < 0.05). On culture-day 21, the growth in the PCL-20%CS group was significantly higher than the other groups (p < 0.05). In conclusion, the PCL-20%CS scaffolds obtained the optimum results in terms of physical properties and cellular response.