Nuttawut Thuaksuban

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.

A comparison of autogenous bone graft combined with deproteinized bovine bone and autogenous bone graft alone for treatment of alveolar cleft.

This study assessed the use of composite autogenous bone and deproteinized bovine bone (DBB) for repairing alveolar cleft compared with autogenous bone alone in terms of clinical outcomes and patient morbidity. 30 patients with a mean age of 10.2±1.7 years were randomly divided into two groups. Group I used autogenous cancellous bone graft harvested from the anterior iliac crests by the conventional trapdoor approach. Group II used a composite of DBB and autogenous cancellous bone harvested by a trephine bone collector; the proportion of 1:1 by volume was used. The bone graft quantities of both groups decreased with time. Their average changes were not statistically different over 24 months after grafting. The canines of both groups could spontaneously or orthodontically erupt through the grafting areas. Patients in group II recovered from uncomfortable walking significantly faster than those in group I (p<0.05) and their duration of hospital stay was significantly shorter than those in group I (p<0.05). The average operation time, intra-operative blood loss and postoperative pain were less in group II than in group I (p>0.05).

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.

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.

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.

Iliac Crest Bone Grafting of the Alveolar Cleft: Clinical and Quantitative Radiographic Assessment

Abstract Objective: To evaluate the clinical results and quantitatively assess bone graft volume after secondary alveolar cleft bone grafting. Materials and Methods: Twenty five patients with alveolar clefts (19 unilateral and 6 bilateral) were enrolled in this prospective study. All alveolar cleft defects were grafted with cancellous bone harvested from the anterior iliac crest and closed by advancement flap. Occlusal X-rays were taken preoperatively, early postoperatively, and 1, 3, 6, 12, 18, and 24 months after the operation. A custom-made film holder was used to control film-to-source distance and angulation, thus permitting a reproducible film position at each time interval. An aluminium step wedge was attached to each film for calibrating the quantitative measurement of radiographic bone density. Assessment of the bone graft was done by measurement of bone density, and bone graft height by image processing and analysis software. Results: The average bone graft volume was 3.30 mL (SD, 1.46 mL). The duration of hospital stay was 5.30 days (SD, 1.02 days). The oronasal fistula was closed in all cases. The canines eventually erupted through the grafted area with the assistance of postoperative orthodontic treatment. Bone graft density in the cleft site rapidly decreased 1 month after the operation, becoming stable after 6 months. The bone graft height significantly decreased over 6 months (p Conclusion: Due to the large amount of cancellous bone available and low surgical morbidity, iliac crest bone grafting remains a promising method for the correction of alveolar cleft defects. However, the high resorption rate of the graft should be considered when choosing the grafting material.

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.