In vitro bioactivity of poly(ε-caprolactone)-apatite (PCL-AP) scaffolds for bone tissue engineering: The influence of the PCL/AP ratio (original) (raw)
Related papers
The International Journal of Artificial Organs, 2006
Porous poly(∊-caprolactone) (PCL) is used as long-term bioresorbable scaffold for bone tissue engineering. The bone regeneration process can be enhanced by addition of carbonated apatites (AP). This study was aimed at evaluating the influence of the PCL/AP ratio on the in vitro degradation and bioactivity of PCL-AP composites. To this purpose, PCL-AP samples were synthesised with the following PCL/AP weight/weight ratios: 50/50, 60/40 and 75/25. Vibrational IR and Raman spectroscopies coupled to thermogravimetry (TG) and differential scanning calorimetry (DSC) were used to investigate the in vitro degradation mechanism in different media: 0.01 M NaOH solution (pH = 12), saline phosphate buffer at pH 7.5 (SPB), esterase in SPB and simulated body fluid (SBF) at pH 7.5. The latter medium was used to evaluate the bioactivity of the composites. A control PCL sample was analysed before the addition of the AP component. As regards the untreated samples, the method of synthesis utilised for...
The International journal of artificial organs, 2006
Porous poly(epsilon-caprolactone) (PCL) is used as long-term bioresorbable scaffold for bone tissue engineering. The bone regeneration process can be enhanced by addition of carbonated apatites (AP). This study was aimed at evaluating the influence of the PCL/AP ratio on the in vitro degradation and bioactivity of PCL-AP composites. To this purpose, PCL-AP samples were synthesised with the following PCL/AP weight/weight ratios: 50/50, 60/40 and 75/25. Vibrational IR and Raman spectroscopies coupled to thermogravimetry (TG) and differential scanning calorimetry (DSC) were used to investigate the in vitro degradation mechanism in different media: 0.01 M NaOH solution (pH=12), saline phosphate buffer at pH 7.5 (SPB), esterase in SPB and simulated body fluid (SBF) at pH 7.5. The latter medium was used to evaluate the bioactivity of the composites. A control PCL sample was analysed before the addition of the AP component. As regards the untreated samples, the method of synthesis utilised...
The influence of polymer blend composition on the degradation of polymer/hydroxyapatite biomaterials
Journal of materials science. Materials in medicine, 2001
The in vitro degradation of biodegradable polymer/ceramic composites was assessed in two different environments under both static and pseudodynamic conditions. The blends, consisting of polycaprolactone, poly(lactic-co-glycolic acid), and hydroxyapatite, have potential use in bone tissue engineering applications, thus it is essential to establish a standardized method of characterizing the degradation of new biomaterials. In this study, the variation in polymer blend ratio was examined to observe a change in degradation rate. The porous blends were degraded in water and serum-containing media. A previous study examined in vitro degradation in serum-free buffer. Molecular weight loss, gravimetric weight loss, pH changes and morphological changes were evaluated. The changes in porosity were observed with scanning electron microscopy and quantitatively assessed using image analysis. There was a significant difference in molecular weight loss and gravimetric weight loss between the blen...
Polymer, 2000
Poly(l-lactic) acid (PLLA), polycaprolactone (PCL), three different copolymers based on poly(l-lactic) acid and polyglycolic acid (PLLA-co-PGA), and their composites with hydroxyapatite obtained from bovine bone (ossein), were tested in order to have information on the thermal, morphological, mechanical and biochemical properties in view of their use as biocompatible/biodegradable materials. Ossein, which is essentially a biological hydroxyapatite, was found to improve the modulus and increase the hydrophilicity of the polymeric substrate. In addition, the size of the ossein particles was found to be critical for the improvement of mechanical properties. Finally, preliminary results on the in vitro biocompatibility of selected blends carried out by using primary cultures of human osteoblasts showed that the presence of hydroxyapatite stimulates a more positive cellular response.
Bioactivity in in situ hydroxyapatite-polycaprolactone composites
Journal of biomedical materials research. Part A, 2006
In our previous work, hydroxyapatite (HAP) was synthesized under two conditions: one in the presence of polyacrylic acid (in situ HAP) and the other in the absence of polyacrylic acid (ex situ HAP). Composites of both HAPs with polycaprolactone (PCL) were investigated for their applicability as scaffolds for bone tissue engineering. In the current work, bioactivity of these composites has been investigated by soaking them in simulated body fluid for different intervals of time. Nucleation and growth mechanism of apatite on these composites has also been investigated. Fourier transform infrared spectroscopy study suggests that although apatite growth starts with an intermediate phase, it completely transforms to HAP after 4 days of soaking. Nanoindentation results suggest that the apatite growing on in situ HAP/PCL composites has much higher hardness and elastic modulus as compared to the apatite growing on ex situ HAP/PCL composites. The apatite grown on the ex situ composites has a...
Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2014
In this study, two different composition gel derived silica-rich (S2) or calcium-rich (A2) bioactive glasses (SBG) from a basic CaOAP 2 O 5 ASiO 2 system were incorporated into poly(e-caprolactone) (PCL) matrix to obtain novel bioactive composite scaffolds for bone tissue engineering applications. The composites were fabricated in the form of highly porous 3D scaffolds using following preparation methods: solvent casting particulate leaching (SCPL), solid-liquid phase separation, phase inversion (PI). Scaffolds containing 21% vol. of each bioactive glass were characterized for architecture, crystallinity, hydrolytic degradation, surface bioactivity, and cellular response. Results indicated that the use of different preparation methods leads to obtain highly porous (60-90%) materials with differentiated morphology: pore shape, size, and distributions. Thermal analysis (DSC) showed that the preparation method of materials and addition of bioactive glass particles into polymer matrix induced the changes of PCL crystallinity. Composites obtained by SCPL and PI method containing A2 SBG rapidly formed a hydroxyapatite calcium phosphate surface layer after incubation in SBF. Bioactive glasses used as filler in composite scaffolds could neutralize the released acidic by-products of the polymer degradation. Preliminary in vitro biological studies of the composites in contact with osteoblastic cells showed good biocompatibility of the obtained materials. Addition of bioactive glass into the PCL matrix promotes mineralization estimated on the basis of the ALP activity. These results suggest that through a process of selection appropriate methods of preparation and bioglass composition it is possible to design and obtain porous materials with suitable properties for regeneration of bone tissue. V C 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 00B: 000-000, 2014.
Tissue Engineering Part A, 2009
The design of composite scaffolds with slow degradation kinetics imposes the assessment of the time-course of degradation to predict the long-term in vitro behavior. In this work, the effect of hydroxyapatite (HA) particles on the hydrolytic degradation of poly e-caprolactone composite scaffold was investigated. The study of accelerated degradation mechanisms in alkaline medium enabled analysing comparable degradation profiles at different times. The accurate qualitative and quantitative study of morphology by scanning electron microscopy supported by image analysis demonstrated only a negligible effect on the structural porosity, to be ascribed to the addition of micrometric HA as a filler. Moreover, by comparing the Raman spectra with thermal analysis (thermogravimetry and differential scanning calorimetry) the role of HA on the composite degradation mechanism was defined, by separately quantifying the contribution of HA particles in the bulk and on the surface, on the bone formation as a function of modifications induced in the pore morphology, as well as physical and chemical properties of the polymer matrix. Indeed, HA particles alter the poly e-caprolactone crystallinity inducing a ''shielding'' effect of the polymer matrix. Meanwhile, the slight reduction of pore size as a function of the increasing HA content and the improvement of the effective hydrophilicity of the scaffolds also influence the degradation by faster mechanisms. Finally, it has been proven that the presence of HA enhances the scaffold bioactivity and human osteoblast cell response, remarking the active role of bioactive signals on the promotion of the surface mineralization and, as a consequence, on the cell-material interaction.
Materials Science and Engineering: C, 2012
Rossells fiber reinforced polypropylene composites were prepared by melt mixing. The fiber content was 20 wt%. Octadecyltrimethoxysilane (OTMS) and maleic anhydride grafted polypropylene (MAPP) were used to improve the adhesion between poly(propylene) (PP) and the fiber. The mechanical, rheological, and morphological properties, and heat distortion temperature (HDT) of the composites were investigated. Tensile strength, impact strength, flexural strength and HDT of MAPP modified PP composites increased with an increase in MAPP content. However, no remarkable effect of MAPP content on the Young's modulus of the composites was found. OTMS resulted in small decreases of tensile strength and Young's modulus, and increase in impact strength. Scanning electron micrographs revealed that MAPP enhanced surface adhesion between the fiber surface and PP matrix.
In Vitro Degradation of Poly(caprolactone)/nHA Composites
Journal of Nanomaterials, 2014
The degradation behavior and mechanical properties of polycaprolactone/nanohydroxyapatite composite scaffolds are studied in phosphate buffered solution (PBS), at 37°C, over 16 weeks. Under scanning electron microscopy (SEM), it was observed that the longer the porous scaffolds remained in the PBS, the more significant the thickening of the pore walls of the scaffold morphology was. A decrease in the compressive properties, such as the modulus and the strength of the PCL/nHA composite scaffolds, was observed as the degradation experiment progressed. Samples with high nHA concentrations degraded more significantly in comparison to those with a lower content. Pure PCL retained its mechanical properties comparatively well in the study over the period of degradation. After the twelfth week, the results obtained by GPC analysis indicated a significant reduction in their molecular weight. The addition of nHA particles to the scaffolds accelerated the weight loss of the composites and incr...
New approach in evaluation of ceramic-polymer composite bioactivity and biocompatibility
Analytical and bioanalytical chemistry, 2017
Regeneration of bone defects was promoted by a novel β-glucan/carbonate hydroxyapatite composite and characterized by Raman spectroscopy, microCT and electron microscopy. The elastic biomaterial with an apatite-forming ability was developed for bone tissue engineering and implanted into the critical-size defects of rabbits' tibiae. The bone repair process was analyzed on non-decalcified bone/implant sections during a 6-month regeneration period. Using spectroscopic methods, we were able to determine the presence of amides, lipids and assign the areas of newly formed bone tissue. Raman spectroscopy was also used to assess the chemical changes in the composite before and after the implantation process. SEM analyses showed the mineralization degree in the defect area and that the gap size decreased significantly. Microscopic images revealed that the implant debris were interconnected to the poorly mineralized inner side of a new bone tissue. Our study demonstrated that the composit...