Self-curing acrylic formulations containing PMMA/PCL composites: properties and antibiotic release behavior

Partially biodegradable acrylic composites containing poly(methyl methacrylate)-poly(epsilon-caprolactone) (PMMA/PCL) systems were prepared by mixing the corresponding PMMA/PCL beads (89:11, 86:14, 83:17, and 77:23 weight ratio) used as solid phase with methyl methacrylate (MMA) (liquid phase) in a solid/liquid ratio of 1.5:1. The physical and chemical microheterogeneity of these beads influenced significantly the curing parameters, because several aspects involved in the polymerization reaction are closely related to both morphology and size distribution of the particles. In vitro behavior was studied by immersion in simulated body fluid at pH = 7.4 and 37 degrees C for more than 8 weeks and the composition was followed by 1H-nuclear magnetic resonance spectroscopy. Approximately 2% wt/wt weight loss was observed after a period of 8 weeks for the composites richest in PCL. Mechanical properties of the dry and wet specimens were evaluated by compressive and tensile tests. In all cases, the presence of PCL in the composites provided a significant decrease in both compressive strength and elastic modulus compared with plain PMMA. Tensile and compressive strength also decreased significantly after 2 weeks of immersion in simulated body fluid compared with dry specimens. The self-curing composites based on PMMA/PCL beads and loaded with 3% wt/wt vancomycin were evaluated as carriers for local release of antibiotics. The composite prepared with beads of PMMA/PCL ratio 86:14 was the most effective. It eluted 64% of the initial drug within the first 5 h, allowing progressive release of nearly the total amount of the initial drug (90%) in approximately 2 months. The results obtained suggest that the described composites can be suitable for antibiotic release in non-load bearing graft applications.     

Effect of molecular weight of poly(epsilon-caprolactone) on interpenetrating network structure,apatite-forming ability,and degradability of poly(epsilon-caprolactone)/silica nano-hybrid materials

The effect of molecular weight of poly(epsilon-caprolactone) (PCL) on the bioactivity of a PCL/silica nano-hybrid containing calcium salt was investigated. Two hybrids were prepared with low and high molecular weight PCLs, respectively, through a sol-gel method. Their bioactivities were evaluated using a simulated body fluid (SBF), which had almost the same ion concentrations with human blood plasma. Fast and uniform nucleation and growth of the apatite crystals were observed to occur all through the hybrid surface when low molecular weight PCL was used, while slow and random nucleation and growth of the apatite crystals were observed to occur when high molecular weight PCL was used, after soaking for 3 days in the SBF. This phenomenon was explained in terms of the distribution and dispersion of silica phase in the hybrid and the ionic activity product of the apatite in the SBF, which were dependent on the free volume and degradation rate of non-bioactive PCL phase, respectively.     

PCL microparticle-dispersed PLGA solution as a potential injectable urethral bulking agent

The PCL microparticle-dispersed PLGA solutions were prepared as a potential injectable urethral bulking agent. The mixture solutions were prepared by mixing polycarprolactone (PCL) microparticles (diameter, 100 approximately 200mum; fabricated by a temperature-induced phase transition method) and poly(dl-lactic-co-glycolic acid) (PLGA) solution (dissolved in tetraglycol to 10wt%) with different PCL microparticle to PLGA solution ratio. The mixture solution was solidified by the precipitation of PLGA when the solution was contact with water. In contact with water, the PCL microparticles exhibited a well-packed structure entrapped in a solidified porous PLGA matrix, which can effectively prevent the microparticle migration in the body and retain its initial volume even after PLGA matrix degradation. The PCL microparticle-dispersed PLGA solution (particle to solution ratio, 45/55 (w/v)) was easily injected through 18G needle into back of hairless mouse (subcutaneously) and stably located at the apply site. The surrounding tissue including blood vessel were gradually infiltrated into the implant up to 8 weeks without the initial injected volume change and with little inflammatory response. The PCL microparticle-dispersed PLGA solution may be a good candidate as an injectable bulking agent for the treatment of urinary incontinence owing to its good injectability, volume retention potential as well as biocompatibility.     

Mechanical characterization of self-curing acrylic cements formulated with poly(methylmethacrylate)/poly(epsilon-caprolactone) beads

New acrylic-based cements were formulated by replacing a mass fraction of 20% of poly(methyl methacrylate) (PMMA) powder by PMMA/poly(epsilon-caprolactone) (PCL) beads (throughout this article all compositions are given as mass fractions, unless specified otherwise). PMMA/PCL beads containing 10 and 30% PCL were synthesized by suspension polymerization. Cements were prepared by replacing part of the PMMA powder of the formulation by an equivalent mass of PMMA/PCL particles. The influence of the PCL content in the beads on the mechanical behavior was assessed by testing the cements in flexure and compression. The addition of PMMA/PCL particles with 10% PCL content resulted in a marked increase in both flexural modulus and flexural strength related to the plain PMMA beads formulation. This improvement was attributed to a decrease in the cured material porosity. Conversely, by the incorporation of beads with 30% PCL content the flexural properties decreased. This behavior was attributed to the debonding of the particles from the matrix, which was revealed by SEM images. The observed compressive yield strength decrease with the increase of PCL content in the beads was attributed to a low degree of adhesion between the heterogeneous particles and the matrix as well as to the plasticizing effect of the PCL.     

Single-dose mucosal immunization with biodegradable microparticles containing a Schistosoma mansoni antigen

The purpose of this work was to assess the immunogenicity of a single nasal or oral administration of recombinant 28-kDa glutathione S-transferase of Schistosoma mansoni (rSm28GST) entrapped by poly(lactide-co-glycolide) (PLG)- or polycaprolactone (PCL)-biodegradable microparticles. Whatever the polymer and the route of administration used, the equivalent of 100 microg of entrapped rSm28GST induced a long-lasting and stable antigen-specific serum antibody response, with a peak at 9 to 10 weeks following immunization. Isotype profiles were comparable, with immunoglobulin G1 being the predominant isotype produced. The abilities of specific antisera to neutralize the rSm28GST enzymatic activity have been used as criteria of immune response quality. Pooled 10-week sera from mice receiving PLG microparticles by the nasal or oral route neutralized the rSm28GST enzymatic activity, whereas sera of mice receiving either PCL microparticles, free rSm28GST, or empty microparticles inefficiently neutralized this enzymatic activity. Finally, this study shows that a single administration of these microparticles could provide distinct and timely release pulses of microencapsulated antigen, which might greatly facilitate future vaccine development.     

Well-defined sulfobetaine-based statistical copolymers as potential antibioadherent coatings

The potential use of novel poly(sulfobetaine) copolymers as antibioadherent coatings was investigated using Pseudomonas aeruginosa as a model microorganism and human macrophages and 3T3 mouse embryonic fibroblasts. Two well-defined statistical copolymers with narrow molecular weight distributions were prepared by group transfer copolymerization of n-butyl methacrylate (nBuMA) with either 10 or 30 mol % 2-(dimethylamino)ethyl methacrylate (DMAEMA). Sulfobetainized nBuMA-DMAEMA copolymers (poly[sulfobetaine-stat-nBuMA]) were obtained by treating these precursor polymers with 1,3-propanesultone under mild conditions. Both proton NMR spectroscopy and elemental microanalyses indicated that essentially all the DMAEMA residues were derivatized in both copolymers. Poly(methyl methacrylate) (PMMA) discs were coated with the sulfobetainized nBuMA-DMAEMA copolymers and the bioadherent properties of these coated materials were compared with those of PMMA. Statistically significantly fewer (p<.05) bacteria, macrophages, and fibroblasts adhered to the poly(sulfobetaine-stat-nBuMA)-coated PMMA than to the uncoated PMMA. The poly(sulfobetaine-stat-nBuMA) copolymer containing the higher proportion (30 mol %) sulfobetainized DMAEMA residues proved to be the more effective antibioadherent coating. The antibioadherent properties of these coating materials may allow the cost-effective production of dirt-resistant, easy to clean work surfaces, bioinert coatings for medical devices, and antifouling coatings for marine, agricultural, and industrial applications.     

Porous poly(L-lactic acid)/apatite composites created by biomimetic process.

Highly porous poly(L-lactic acid)/apatite composites were prepared through in situ formation of carbonated apatite onto poly(L-lactic acid) foams in a simulated body fluid. The highly porous polymer foams (up to 95% porosity) were prepared from polymer solution by solid-liquid phase separation and subsequent sublimation of the solvent. The foams were then immersed in the simulated body fluid at 37 degrees C to allow the in situ apatite formation. After incubation in the simulated body fluid for a certain period of time, a large number of characteristic microparticles formed on the surfaces of pore walls throughout the polymer foams. The microparticles were characterized with scanning electron microscopy, energy dispersive spectroscopy, Fourier transform IR spectroscopy, and X-ray diffractometry. These porous spherical microparticles were assemblies of microflakes. They were found to be carbonated bonelike apatite. A series of composite foams with varying sizes and concentrations of the apatite particles was obtained by varying incubation time and conditions. These porous composites may be promising scaffolding materials for bone tissue engineering and regeneration because the excellent bone-bonding properties of the apatite may provide a good environment for osteoblast and osteoprogenitor cells' attachment and growth.     

紫杉醇聚己内酯／泊洛沙姆188共混载药微球及其抗肿瘤活性

目的本研究首次尝试利用聚己内酯（PCL）与亲水性添加剂泊洛沙姆188（Pluronic F68,F68）共混物作为载体材料与抗癌药物紫杉醇组成微球缓释载药系统。方法采用乳化,溶剂挥发法制备紫杉醇PCL/F68共混微球;考察紫杉醇PCL／F68共混微球的表面形态、平均粒径、包埋率及体外释放性能：利用DSC法分析紫杉醇在PCL／F68共混徽球中的分散状态;考察紫杉醇PCL/F68共混微球在小鼠肝癌H22腹水瘤模型中的抗肿瘤活性。结果表明载体材料中的亲水性添加剂F68可在微球表面形成孔状结构,F68的加入提高了紫杉醇从PCL／F68共混载药微球的释放并获得了接近恒定的释放性能;在小鼠肝癌H22腹水瘤模型中。紫杉醇PCL／F68共混载药微球对肿瘤生长具有抑制作用,荷瘤小鼠生存期明显延长。结论以PCL/F68共混物为载体制备的紫杉醇控释微球具有较高的释放能力和明显的控释效果．     

PCL microspheres based functional scaffolds by bottom-up approach with predefined microstructural properties and release profiles

Advanced tissue engineering approaches rely upon the employment of biomaterials that integrate biodegradable scaffolds with growth factor delivery devices to better guide cellular activities and enhance tissue neogenesis. Along these lines, here we proposed a bottom-up approach for the realization of bioactive scaffolds with controllable pore size and interconnection, combined with protein-loaded polymeric microcarriers acting as local chrono-programmed point source generation of bioactive signals. Bioactive scaffolds are obtained through the thermal assembly of protein activated poly(epsilon-caprolactone) (PCL) microspheres prepared by double emulsion and larger protein free PCL microspheres obtained by single emulsion. It is shown that the pore dimension, interconnectivity and mechanical properties in compression of the scaffold could be predefined by an appropriate choice of the size of the protein-free microparticles and process conditions. Protein-loaded microparticles were successfully included within the scaffold and provided a sustained delivery of a model protein (BSA). These matrices offer the possibility to concurrently modulate and control the size and extension of the porosity, mechanical properties and the spatial-temporal distribution of multiple bioactive signals.     

Intradermal immunization with ovalbumin-loaded poly-ɛ-caprolactone microparticles conferred protection in ovalbumin-sensitized allergic mice

BACKGROUND: Although immunotherapy has been reported as the only treatment able to revert the T-helper type 2 (Th2) response, its administration has some disadvantages such as the requirement of multiple doses, possible side-effects provoked by conventional adjuvants and the risk of suffering an anaphylactic shock. For these reasons, drug-delivery systems appear to be a promising strategy due to its ability to (i) transport the allergens, (ii) protect them from degradation, (iii) decrease the number of administrations and (iv) act as immuno-adjuvants. OBJECTIVE: The aim of this work was to evaluate the properties of poly-epsilon-caprolactone (PCL) microparticles as adjuvants in immunotherapy using ovalbumin (OVA) as an allergen model. For this purpose, the protection capacity of these microparticles (OVA PCL) against OVA allergy was studied in a murine model. METHODS: The humoral and cellular-induced immune response generated by OVA encapsulated into PCL microparticles was studied by immunizing BALB/c mice intradermically. Also, OVA-sensitized mice were treated with OVA PCL and OVA adsorbed to aluminium hydroxide (OVA-Alum). Fifteen days after therapy, animals were challenged with OVA and different signs of anaphylactic shock were evaluated. RESULTS: One single shot by an intradermal route with OVA PCL resulted in a Th2-type immune response. In OVA-sensitized mice, treatment with OVA PCL elicited high OVA-specific IgG but low levels of IgE. Furthermore, OVA PCL mice group displayed lower levels of serum histamine and higher survival rate in comparison with the positive control group. CONCLUSION: The anaphylactic shock suffered by OVA PCL-treated mice was weaker than the one induced in the OVA-Alum group. Hence, the intradermal immunization with OVA PCL microparticles induced hyposensitization in OVA-allergic mice.     

Structure and biological functions of human IgD. XIV. The development of a solid-phase radioimmunoassay for the quantitation of IgD in human sera and secretions.

A simple but sensitive radioimmunoassay method for the quantitation of IgD in sera and body fluids has been developed. Specifically purified chicken anti-delta was covalently coupled to cyanogen bromide activated filter paper discs and the discs were incubated together with the samples to be analyzed. The washed discs were next incubated with 125-I-labeled specifically purified chicken or rabbit anti-human delta-antibodies. IgD on the disc was quantified by reference to a standard curve prepared with purified human IgD. The sensitivity of this assay was approximately 10 ng/ml IgD. IgD was demonstrable in cord sera (18 of 18), hypogammaglobulinemic sera (15 of 15), amniotic fluids (6 of 6), salivas (8 of 10), normal cerebrospinal fluids (12 of 13) and cerebrospinal fluids from patients with subacute sclerosing panencephalitis (5 of 5). The finding of IgD in human secretions raises the interesting possibility that IgD may be a secretory antibody.     

紫杉醇聚己内酯／泊洛沙姆188载药纳米粒及其抗肿瘤活性

目的利用聚己内酯（PCL）与亲水性添加剂泊洛沙姆188（F68）共混物作为载体材料与抗癌药物紫杉醇组成纳米粒缓释载药系统,并评价其在裸鼠人乳腺癌B37实体瘤模型中的抗肿瘤效果。方法采用超声乳化／溶剂挥发法制备紫杉醇PCL/F68载药纳米粒：对紫杉醇PCI／F68载药纳米粒进行表征及高压液相色谱法（HPLC）测定包封率和体外释放度：利用差示扫描热分析（DSC）法分析紫杉醇在PCL／F68载药纳米粒中的分散状态;评价紫杉醇PCL／F68载药纳米粒在裸鼠人乳腺癌B37实体瘤模型中的抗肿瘤活性．结果紫杉醇PCL/F68载药纳米粒呈现规整的球形：平均粒径为150．50nm（标准差25．41nm）．多分散系数为O．18。紫杉醇PCI仃68纳米粒的载药量为18％,药物包封率为84-36％。紫杉醇PCIJF68载药纳米粒体外药物释放研究表明在50d的释放周期内累计释放量约为49％,接近零级释放（R=0．998）。体内抗肿瘤活性实验研究表明．紫杉醇PCL/F68载药纳米粒对裸鼠人乳腺癌B37实体瘤生长具有明显抑制作用。结论肿瘤局部注射紫杉醇PCL/F68载药纳米粒能够有效地抑制肿瘤的生长,     

Simple surface modification of poly(epsilon-caprolactone) to induce its apatite-forming ability

A biodegradable polymer coated with a bone-like apatite layer on its surface is useful as a scaffold for bone tissue regeneration. In this work, a poly(epsilon-caprolactone) (PCL) surface was modified by an O2 plasma surface treatment to form oxygen-containing functional groups. The plasma-treated samples were subsequently dipped alternately in an alcoholic solution containing calcium ions and one containing phosphate ions to deposit apatite precursors on the surface. The surface-modified PCL samples formed a dense and uniform surface bone-like apatite layer after immersion for 24 h in a simulated body fluid with ion concentrations approximately equal to those of human blood plasma. This surface-modification process is applicable to two-dimensional PCL plates and three-dimensional PCL meshes. In the resulting apatite-PCL composite, the apatite layer strongly adhered to the PCL surface and remained intact after a tape-detachment test. Therefore, this type of composite material will be a useful scaffold for bone tissue engineering.     

Osteoblast cell death on methacrylate polymers involves apoptosis

The success of an implant depends on the implant-tissue interface. There are many causes of implant failure, one of which is tissue necrosis. The aim of this in vitro study was to determine whether cell death of primary human osteoblasts (implant site specific cells) occurred by apoptosis (a form of programmed cell death) on two methacrylate polymers. Cells were cultured on poly(ethyl methacrylate)/tetrahydrofurfuryl methacrylate and poly(methyl methacrylate in the form of 13-mm discs, in conditioned medium containing leachable monomer and in the presence of various concentrations of monomer itself in the culture medium. It was found that monomer and leached monomer caused apoptosis of human osteoblast cells in this system. Tetrahydrofurfuryl methacrylate monomer was found to be more toxic than currently used monomer methylmethacrylate. Preincubation of polymers in serum containing medium was found to increase the biocompatibility of the polymers. High levels of apoptosis occurred on polymer used directly after polymerization. Apoptosis levels were decreased after polymer was incubated at 60 degrees C overnight or for 3 days. Apoptosis therefore may occur in cells at the implant site in vivo.     

Inversion of Phase Morphology in Polymer‐Blend Thin Films on Glass Substrates

Summary: The phase‐morphology inversion in two blend systems of polystyrene/poly(methyl methacrylate) (PS/PMMA) and polystyrene/poly(ε‐caprolactone) (PS/PCL) has been studied after their thin films were prepared on glass substrates by spin‐coating from a co‐solvent tetrahydrofuran (THF). Phase‐contrast microscopy (PCM), scanning‐electron microscopy (SEM) equipped with energy dispersive X‐ray spectroscopy (EDS), and atomic force microscopy (AFM) were used to obtain information on the morphology of the thin films during heat treatment. It was found that the PMMA‐rich and PCL‐rich phases are always continuous after annealing in either of the PS/PMMA and PS/PCL blend thin films, even though the PMMA and PCL are minor components in the blends. This should result from the better wetting abilities of PMMA and PCL on a glass substrate than PS in the blends. The effect of the viscosity in the evolution of the phase structure was also investigated by changing the molecular weight of PS in the PS/PCL blend thin films. Further more, it is found that the phase‐separation process and the wetting phenomenon of the blends on the glass substrate can be strongly suppressed after adding PS‐block‐PMMA diblock copolymer to the PS/PMMA blend system as a compatibilizer.

Scheme of the longitudinal section of the evolution of the phase structure of a PS:PMMA (70:30 w:w) blend film.     

Polymeric matrices based on graft copolymers of PCL onto acrylic backbones for releasing antitumoral drugs

Graft copolymers of poly(epsilon-caprolactone) (PCL) on poly(dimethylacrylamide) (PDMAm), poly(methylmethacrylate) (PMMA), or on copolymers of poly(DMAm-co-MMA) have been synthesized and characterized by (1)H NMR spectroscopy, differential scanning calorimetry (DSC), and size exclusion chromatography (SEC). These partially biodegradable copolymer matrices have been proposed as drug delivery systems for the release of low-molecular-weight glycosides. Octyl-N-acetyl-6-O-[2,2-bis(hydroxymethyl)-3-hydroxypropyl]-alpha-D-glucosamide, a synthetic carbohydrate able to inhibit the proliferation of human malignant glioma cells in culture and transplanted glioma in rats was selected as drug model. The in vitro aqueous behavior of four drug-loaded and unloaded graft copolymers of different MMA: DMAm and PCL ratios has been analyzed performing swelling, degradation, and drug release experiments. An intimate dependence of the aqueous behavior with the composition has been found. The higher was the DMAm content, the higher was the hydrophilicity of the synthesized systems as well as the swelling, degradation, and drug release rate. In vivo experiments in pigs demonstrated the very good tolerance of drug-loaded implanted polymeric discs, and that >95% of the charged drug is released after 2 months' implantation.     

Biocompatibility of elastin-like polymer poly(VPAVG) microparticles: in vitro and in vivo studies

Poly(L-valine-L-proline-L-alanine-L-valine-L-glycine) (VPAVG) is a new kind of proteinaceous polymer belonging to the Elastin-like family. These polymers are based on the recurrence of certain short peptide monomers that are considered as "building blocks" in the natural elastin. This smart thermoresponsive polymer has the ability to self-associate at physiological temperature to form aggregates with about 60% in water. This ability can be harnessed to prepare microparticles loaded with an active substance. The aim of this report is to evaluate, from the results of the experiment conducted, the biocompatibility of microparticles prepared from poly(VPAVG). We have studied the cytotoxic effects of microparticles, edema formation after subcutaneous injection (1 and 2.5 mg) in rats (n = 6), and also intraocular tolerance after the intravitreal injection of 2.5 mg of poly(VPAVG) microparticles into pigmented rabbits (n = 12). The polymer did not induce any cytotoxicity or nonspecific depression of cellular respiration on macrophages under the range of polymer concentrations investigated in this study (20, 30, 40, and 60 mg/mL). We observed no inflammatory response to microparticles after subcutaneous injection in the hind-paw of rats, with no significant differences between the control group (PBS) and experimental groups. Anterior and posterior segment signs were evaluated after intraocular injection of poly(VPAVG) microparticles. Only a few eyes (2/11) of the experimental group presented inflammation signs at day 28 postinjection. Nevertheless, 45% (5/11) of the eyes receiving microparticles showed tractional retinal detachment. The results observed in this work suggested certain fibroblastic activity induced by poly(VPAVG) microparticles after their intraocular injection.     

Bone-like apatite-forming ability and mechanical properties of poly(epsilon-caprolactone)/silica hybrid as a function of poly(epsilon-caprolactone) content

Effect of poly(epsilon-caprolactone) (PCL) content on the bioactivity and mechanical properties of PCL/silica hybrid was investigated. The PCL/silica hybrids with different PCL contents were prepared through co-condensation reaction with triethoxysilane end capped PCL and tetraethyl orthosilicate. The higher the PCL content in the hybrid, the lower the apatite-forming rate and showed polymer-like ductile-tough fracture behavior. On the contrary, the lower the PCL content in the hybrid, the higher the apatite-forming rate and showed ceramic-like hard-brittle fracture behavior. At the intermediate PCL content, the apatite-forming rate and its mechanical properties showed also intermediate behaviors. The highest tensile strength and Young's modulus could be obtained at intermediate PCL content and they were around 20 and 600 MPa, respectively, while the strain at failure was around 50%. This new kind of hybrid material is likely to have the potential to be used as a bone repairing material because of its apatite-forming ability and the mechanical properties comparable to human cancellous bone.     

Taxol-loaded block copolymer nanospheres composed of methoxy poly(ethylene glycol) and poly(epsilon-caprolactone) as novel anticancer drug carriers

We prepared the methoxy poly(ethylene glycol) (MePEG)/poly(epsilon-caprolactone) (PCL) amphiphilic block copolymeric nanospheres containing taxol which has promising anticancer activity. MePEG/PCL block copolymeric nanospheres (MEP50) showed a narrow size distribution and an average diameter of less than 100 nm. When the initial weight ratio of taxol to polymer was 0.5:1.0, we could obtain the nanospheres having a relatively high drug-loading of more than about 20%. The size of the MePEG/PCL nanospheres also increased according to the taxol loading. However, the nanospheres did not exhibit a significant change in the size distribution and also showed a size of less than 100 nm for even that with drug-loading content (DLC) of about 20%. From the 1H NMR analysis, we identified that the MePEG/PCL nanospheres prepared by dialysis procedure have core-shell structure consisting of the hydrophilic outer shell of MePEG and the hydrophobic inner core of PCL. We confirmed the low toxicity of MePEG/PCL nanospheres (MEP70) in the acute toxicity study using male ICR mice. In addition, considering the extremely lipophilic characteristics of taxol, this MePEG/PCL, nanosphere system with high taxol loading content and suspended properties in water could be useful for the delivery of taxol.     

Preparation and characterization of novel poly(ε-caprolactone)/biphasic calcium phosphate hybrid composite microspheres

Desirably porous biodegradable hybrid composite microspheres were fabricated for use in bone graft and bone substitute applications. In this study, novel poly(ε-caprolactone)/biphasic calcium phosphate (70/30) composite microspheres (PCL/BCP MPs) were prepared using the emulsion solvent-evaporation method. Throughout this process, the ammonium bicarbonate (NH?HCO?) content was changed to obtain the desired porous structure. However, to maintain the spherical shape, the NH?HCO? content should not be higher than 5%. In the optical images of the PCL/BCP MPs, almost all the microparticles had a spherical shape, and the average diameter was about 600 μm. The scanning electron microscopy and cross-sectional optical images showed that the pore density and pore diameter of PCL/BCP MPs increased with increasing initial NH?HCO? concentrations. In the phase-composition analysis of the PCL/BCP MPs, which was characterized by X-ray diffraction and EDS, the two crystals BCP and PCL phases were shown to be miscible in PCL/BCP MPs. When the degradation of these microspheres was characterized, PCL/BCP MPs-0, PCL/BCP MPs-2, and PCL/BCP MPs-5 were found to display a sustained biodegradability, and the rate of degradation increased at higher initial NH?HCO? concentrations. Proliferation of cells on three different sample types was assessed and compared, and based on these results, the PCL/BCP MPs-5 was chosen to study MG-63 osteoblast-cell adhesion, growth, and proliferation. Furthermore, confocal images indicated that the cells effectively adhered, spread, and proliferated on PCL/BCP MPs-5 during a 5-day culture period.