Protein encapsulated in electrospun nanofibrous scaffolds for tissue engineering applications

The main purpose of tissue engineering is the preparation of fibrous scaffolds with similar structural and biochemical cues to the extracellular matrix in order to provide a substrate to support the cells. Controlled release of bioactive agents such as growth factors from the fibrous scaffolds improves cell behavior on the scaffolds and accelerates tissue regeneration. In this study, nanofibrous scaffolds were fabricated from biocompatible and biodegradable poly(lactic‐co‐glycolic acid) through the electrospinning technique. Nanofibers with a core–sheath structure encapsulating bovine serum albumin (BSA) as a model protein for hydrophilic bioactive agents were prepared through emulsion electrospinning. The morphology of the nanofibers was evaluated by field‐emission scanning electron microscopy and the core–sheath structure of the emulsion electrospun nanofibers was observed by transmission electron microscopy. The results of the mechanical properties and X‐ray diffraction are reported. The scaffolds demonstrated a sustained release profile of BSA. Biocompatibility of the scaffolds was evaluated using the MTT (3(4,5‐ dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay for NIH‐3T3 fibroblast cells. The results indicated desirable biocompatibility of the scaffolds with the capability of encapsulation and controlled release of the protein, which can serve as tissue engineering scaffolds. © 2013 Society of Chemical Industry     

Effects of the methyl methacrylate addition,polymerization temperature and time on the MBG@PMMA core-shell structure and its application as addition in electrospun composite fiber bioscaffold

Mesoporous bioactive glass (MBG) possesses a high specific surface area and excellent biocompatibility making it a promising biomaterial. In the present study, poly(methyl methacrylate) (PMMA) was coated on MBG to obtain a MBG@PMMA core-shell structure to further expand the potential applications of MBG. Changes in the MMA to MBG ratio, polymerization temperature and time were investigated to determine their effects on the core-shell structure. The as-prepared core-shell powders were evaluated using scanning electron microscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy to determine the optimal core-shell structure for electrospinning application. Electrospun composite fiber scaffolds prepared by adding MBG with or without an optimized PMMA shell were examined through microstructural observation, mechanical testing, Raman spectroscopy, and in vitro bioactivity evaluation. Experimental results showed that optimized MBG@PMMA core-shell powder was prepared using MMA: MBG = 3: 1, with polymerization at 70 °C for 4 h. The spherical core-shell powder exhibited a relatively smooth surface and the flake- or cotton-like shell structure was beneficial to electrospinning. Electrospun composite fiber scaffold prepared using MBG@PMMA powder exhibited superior mechanical performance and excellent biocompatibility compared to its shell-less MBG counterpart.     

Controllable Aligned Nanofiber Hybrid Yarns with Enhanced Bioproperties for Tissue Engineering

Electrospun nanofibers have large surface area, high porosity, and controllable orientation while conventional microfibers have appropriate mechanical properties such as stiffness, strength, and elasticity. Therefore, the combination of nanofibers and microfibers can provide building elements to engineer biomimetic scaffolds for tissue engineering. In this study, a core–shell structured fibrous structure with controllable surface topography is created by electrospinning polycaprolactone (PCL) nanofibers onto polyglycolic acid (PGA) microfibers. The surface morphology, surface wettability, and mechanical properties of the resultant core–shell structure are characterized. FE‐SEM images reveal that the orientation of PCL nanofibers on the yarn surface can be tuned by a fiber collector and rotating disks. Benefiting from the introduction of a shell of aligned PCL nanofibers on the core of PGA yarn, the uniaxially aligned PCL nanofiber–covered yarns (A‐PCLs) exhibit higher hydrophilicity, porosity, and mechanical properties than the core PGA yarns. Moreover, A‐PCLs promote the adhesion and proliferation of BALB/3T3 (mouse embryonic fibroblast cell line), and guide cell growth along the biotopographic cues of the PCL nanofibers with controllable alignment. The developed core–shell yarn having both the desired surface topography of PCL nanofibers and mechanical properties of PGA microfibers demonstrates great potential in constructing various tissue scaffolds.     

碳纤维增强聚合物组织工程支架的制备及表征

以碳纤维（CF）作为增强材料,将CF有序排列于聚乳酸羟基乙酸（PLGA）多孔结构中,制备性能优良的CF/PLGA复合支架,并对其力学性能及细胞生物学性能进行表征.对增强体CF进行有序排列以提高支架的力学性能,扫描电子显微镜（SEM）观察CF/PLGA复合支架的微观形貌,可以看出CF在聚合物基体内部是呈有序结构并且二者结合情况良好.为了提高CF的生物相容性,利用对氨基苯甲酸对CF进行表面修饰,细胞生长在支架上的SEM照片反映了成纤维细胞对PLGA及CF/PLGA复合支架的黏附性能良好;通过细胞毒性测试,发现表面修饰的CF对细胞的生长没有负面作用,且在一定程度上促进了细胞的生长.研究结果表明,制备的CF/PLGA支架具有良好的力学性能和生物相容性,在骨组织工程支架的应用中具有一定的潜力.     

Development by robocasting and mechanical characterization of hybrid HA/PCL coaxial scaffolds for biomedical applications

Porous structures consisting of a tetragonal three-dimensional mesh of interpenetrating coaxial tubes were fabricated by robocasting from hydroxyapatite (HA) inks. After sintering the structures, polycaprolactone (PCL) was infiltrated within the tubes core by injection of a polymer solution. The addition of the polymer enhanced the mechanical performance in terms of toughness over dense- and hollow-strut all-ceramic scaffolds, specially under bending stresses. PCL impregnation improved also the compressive strength over hollow-strut scaffolds —although dense-strut structures remained stronger especially in compression. Thus, this coaxial core-shell strut configuration combines the best features of each material: the necessary stiffness and excellent osteoconductivity of the bioceramic, with the high toughness and ductility of the biopolymer; and allows the fabrication of hybrid scaffolds with the interconnected macroporosity necessary for cell ingrowth. Hence, this work successfully provides a proof-of-concept of this novel strategy for the mechanical enhancement of bioceramic-based scaffolds while preserving their osteoconductive properties.     

Functionalized tricalcium phosphate and poly(3-hydroxyoctanoate) derived composite scaffolds as platforms for the controlled release of diclofenac

Novel bone substitutes such as highly porous ceramic scaffolds can serve as platforms for delivering active molecules. A common problem is to control the release of the drug, therefore, it is beneficial to use a drug-functionalized polymer coating. In this study, β-tricalcium phosphate-based porous scaffolds were obtained and coated with diclofenac-functionalized biopolymer – poly(3-hydroxyoctanoate) – P(3HO). To the best of our knowledge, studies using P(3HO) as a component in ceramic-polymer based drug delivery system for bone tissue regeneration have not yet been reported. Presented materials were comprehensively investigated by various techniques such as powder X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, hydrostatic weighing and compression tests, pH and ionic conductivity measurements, high-performance liquid chromatography and in vitro cytotoxicity studies. The obtained diclofenac-loaded composite was not only characterised by controlled and sustained drug release, but also possessed improved mechanical properties. Moreover, the precipitation of apatite-like forms on its surface was observed after incubation in simulated body fluid, which indicates its bioactive potential. After 24 hours no cytotoxic effect on MC3T3-E1 mouse preosteoblastic cells was confirmed using indirect cytotoxicity studies. Thus, this promising multifunctional composite scaffold can be a promising candidate as an anti-inflammatory drug-delivery system in bone tissue engineering.     

Aligned core/shell electrospinning of poly(glycerol sebacate)/poly(l‐lactic acid) with tuneable structural and mechanical properties

In an earlier study, scaffolds of biodegradable poly(glycerol sebacate) (PGS)/poly(l ‐lactic acid) (PLLA) core/shell fibres had been fabricated using a core/shell electrospinning method, and the scaffolds were found to have mechanical properties similar to those of natural soft tissues, excellent cytocompatibility and slow degradation rate. In this paper, PGS/PLLA core/shell fibre mats with tuneable degrees of fibre alignment were fabricated using core/shell electrospinning with a rotating fibre collection mandrel. An increase in the rotational speed raised the degree of fibre alignment in the fibre mats. Single and cyclic tensile testing of the mats showed that an increase in the fibre alignment raised the modulus, resilience, ultimate tensile strength (UTS) and elongation up to a maximum at 1000 or 1500 rpm, but the resilience, UTS and elongation decreased when the rotational speed was further raised to 2000 rpm. Nonlinearly elastic biomaterials with a large range of mechanical properties were successfully fabricated using this method and the aligned fibre structure may be capable of guiding the growth of attached cells. © 2016 Society of Chemical Industry     

Synthesis and characterization of cross-linked poly(acrylic acid)-poly(styrene-alt-maleic anhydride) core-shell microcapsule absorbents for cement mortar

We synthesized core-shell microcapsule absorbents with cPAA (cross-linked poly(acrylic acid)) as the core and PSMA (poly(styrene-alt-maleic anhydride)) as the shell by precipitation polymerization, where the shell served to delay the absorption of excess water in cement mortars. To control shell thickness, the cPAA-PSMA capsules were synthesized with core monomer mass to shell monomer mass ratios of 1/0.5, 1/1, and 1/1.5. We observed the hydrolysis of the PSMA polymer in a cement-saturated aqueous solution by Fourier transform infrared (FT-IR) spectroscopy. Furthermore, core-shell structures were observed for 1/1 (cPAA-PSMA #3) and 1/1.5 (cPAA-PSMA #4) core/shell monomer mass ratios, whereas no core-shell structures were observed for the 1/0.5 (cPAA-PSMA #2) microcapsules by transmission electron microscopy (TEM).     

Incorporation of graphene oxide and calcium phosphate in the PCL/PHBV core-shell nanofibers as bone tissue scaffold

Bone tissue scaffolds should have both desired mechanical stability and cell activities including biocompatibility, cell differentiation, and maturation. Also, suitable mineralization is another key factor for these materials. Hence, in current work, in order to achieve a scaffold with desired mechanical and bioactivity properties, core-shell nanofibers based on the polycaprolactone and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with different concentration of graphene oxide (GO) (0.5, 1, and 1.5 wt%) and calcium phosphate (CP) (1 and 3 wt%) were prepared to utilize as bone scaffold. Microstructure of nanofibers observed by field emission scanning electron microscope (FE-SEM) and results exhibited that the most of nanofibers had 270–500 nm diameter. Attenuated total reflectance Fourier transform infrared spectroscopy and energy dispersive X-ray evaluations verified appearance of GO and CP into the electrospun scaffolds (ES). Transmission electron microscopy analysis endorsed core-shell structure of nanofibers. X-ray diffraction study moreover determination of semicrystalline structure, verified presence of GO and CaPO₄ into the nanofibers. Water contact angle demonstrates that, ES2 and ES3 situated in suitable domain of hydrophilicity. Tensile analysis determined that, ES2, ES3, and ES4 had the highest mechanical properties for use as bone scaffold. Cell viability assessment confirmed biocompatibility of scaffold during 7 days. Alkaline phosphatase and alizarin red staining exhibited maturating and differentiating of osteocytes after 21 days seeding on the scaffolds.     

Preparation and characterization of composite resin by vinyl chloride grafted onto poly(BA-EHA)/poly(MMA-St)

Crosslinked poly(butyl acrylate-co-2-ethylhexyl acrylate)/poly(methyl methacrylate-co-styrene) (ACR I) latex was synthesized by multi-stage emulsion polymerization. A series of grafting vinyl chloride (VC) composite latices were prepared by emulsion copolymerization in the presence of core-shell ACR I latex. The effects of ACR I amount and its core/shell ratio on particle diameters of the composite latices and mechanical properties of the prepared materials were investigated. The grafting efficiency (GE) of VC grafted onto ACR I increases with an increasing ACR I content. Transmission electron microscope (TEM) study indicates that ACR I latex particles have a regular core-shell structure obviously. However, when styrene content in the shell of ACR I is more than 70 percent of the shell by weight, ACR I latex particles have an irregular core-shell morphology like sandwich. The composite latex particles synthesized by core-shell ACR I latex grafting VC have a clear three-layered core-shell structure. Dynamic mechanical analysis (DMA) study reveals that the compatibility between ACR I and PVC is well improved. With increasing ACR I content, the loss peak in low temperature range for every composite sample becomes stronger and stronger and gradually shifts to a higher temperature. Scanning electron microscope (SEM) graphs showed that the fractured surface of the composite sample exhibited better toughness of the material. TEM graphs showed that ACR I was uniformly dispersed in the PVC matrix.     

Fabrication and characterization of electrospun fibrous nanocomposite scaffolds based on poly(lactide‐co‐glycolide)/poly(vinyl alcohol) blends

Tissue engineering involves the fabrication of three‐dimensional scaffolds to support cellular in‐growth and proliferation. Ideally, the scaffolds should be similar to the native extracellular matrix (ECM). Electrospun polymer nanofibrous scaffolds are appropriate candidates for ECM mimetic materials since they mimic the nanoscale properties of ECM. Electrospun polymer nanocomposites based on poly(lactide‐co‐glycolide) (PLGA)/poly(vinyl alcohol) (PVA) and organically modified montmorillonite (OMMT) were prepared by a solution intercalation technique followed by electrospinning. The morphology of fibrous scaffolds based on these nanocomposites was investigated using scanning electron microscopy. The scaffolds showed highly porous structure within the nanofibres of diameters ranging from 400 to 700 nm. X‐ray diffractometry gave evidence of good dispersion of the OMMT in the blends with exfoliated morphology. Measurements of the water uptake and water contact angle of the fibrous scaffolds indicated significant improvement in the hydrophilicity of the scaffolds. Evaluations of the mechanical properties and unrestricted somatic stem cell culture of the electrospun fibrous nanocomposite scaffolds revealed that the PLGA90/PVA10/1.5% OMMT and PLGA90/PVA10/3% OMMT samples are the most useful from the tissue engineering application viewpoint. Copyright © 2010 Society of Chemical Industry     

Synthesis,characterization and in-vitro behavior of natural chitosan-hydroxyapatite-diopside nanocomposite scaffold for bone tissue engineering

Composite materials based on a combination of biodegradable polymers and bioactive ceramics, including chitosan and hydroxyapatite are discussed as suitable materials for scaffold fabrication. Diopside is a member of bioactive silicates; it is a good choice for hard tissue engineering because of its biocompatibility with host tissue and high mechanical strength. Chitosan and hydroxyapatite were extracted from shrimp shell and bovine bone, respectively and diopside nanoparticles were prepared by the sol-gel method. The present study reports on a chitosan composite which was reinforced by hydroxyapatite and diopside; the scaffolds were fabricated by the freeze-drying method. The so-produced chitosan-hydroxyapatite-diopside (CS-HA-DP) scaffolds were further cross-linked using tripolyphosphate (TPP) to achieve enhanced mechanical strength. The ratios of the ceramic components in composites were 5-58-37, 10-55-35, and 15-52-33 (diopside-hydroxyapatite-chitosan, w/w %). The physicochemical properties of scaffolds were investigated using Fourier-transform infrared spectrometry (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) techniques. The effect of scaffolds composition on bioactivity and biodegradability were studied well. To investigate mechanical properties of samples, compression test was done. Results showed that the composite scaffold with 5% DP has the highest mechanical strength. The porosity of composites dropped from 92% to 76% by increasing the amount of DP. Cytocompatibility of the scaffolds was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, alkaline phosphatase (ALP) activity, and cell attachment studies using human osteoblast cells. Results demonstrated no sign of toxicity and cells were found to be attached to the pore walls within the scaffolds; moreover, results illustrated that the developed composite scaffolds could be a potential candidate for tissue engineering.     

Bioactive glass based scaffolds incorporating gelatin/manganese doped mesoporous bioactive glass nanoparticle coating

We investigated the bioactivity and cytocompatibility of 45S5 bioactive glass (BG) based scaffolds coated with a composite layer formed by gelatin and manganese doped mesoporous bioactive glass nanoparticles (Mn-MBGNs). The scaffolds were prepared using the foam replica method, and they were further coated with Mn-MBGNs/gelatin via dip coating. The synthesized scaffolds were characterized in relation to morphology, porosity, mechanical stability, bioactivity and cell biology behavior using osteoblast-like (MG-63) cells. The scaffolds were highly porous with interconnected porosity, and a suitable pore structure was maintained even after the Mn-MBGNs/gelatin coating. Energy-dispersive X-ray spectroscopy (EDX) confirmed the presence of Mn-MBGNs in the coatings. Moreover, the presence of gelatin was confirmed by Fourier transform infrared spectroscopy (FTIR). The coated scaffolds exhibited in-vitro bioactivity in simulated body fluid comparable to that of uncoated BG scaffolds. Finally, Mn-MBGNs/gelatin coated scaffolds were shown to be non-cytotoxic to MG-63 cells. Hence, the results presented here confirm that the novel Mn containing scaffolds can be considered in the field of biologically active ion releasing scaffolds for bone tissue engineering applications.     

PBT/PC工程塑料低温抗冲改性剂的研制

以丁二烯、苯乙烯和甲基丙烯酸甲酯为聚合单体,采用种子乳液聚合方法制备具有核-壳结构的高分子聚合物,核芯是交联结构的聚丁二烯橡胶相,外部是甲基丙烯酸甲酯壳层,它与PBT（聚对苯二甲酸丁二酯）和PC（聚碳酸酯）的共混合金有良好的相容性,用于PBT/PC工程塑料低温抗冲改性剂,能显著提高材料的力学性能,特别是低温抗冲击性能.     

聚己内酯/壳聚糖核壳结构纤维引导组织再生膜的制备及表征

高性能的引导组织再生膜是牙周引导组织再生术成功的关键,静电纺丝法因可仿生制备类细胞外基质结构,在引导组织再生膜研制方面显示出巨大潜力。本研究通过同轴静电纺丝法,以聚己内酯（PCL）为核层,壳聚糖（CS）为壳层,制备核壳结构的纳米纤维,并用香草醛对制备的纤维膜进行交联。利用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X 射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、力学测试及细胞培养等手段对制备的纤维膜进行形貌、内部结构、化学组成、力学性能和细胞相容性表征。结构分析表明本研究成功制备了核壳结构的PCL-CS纤维膜。力学测试和亲疏水性测试结果表明交联后的纤维膜具有较好的耐水性和力学性能,断裂强度高出文献报道值近两倍;体外细胞培养结果显示MG-63细胞能在交联后的纤维膜上黏附和持续增殖,表明纤维膜具有较好的细胞相容性,在引导组织再生领域有较好的应用前景。     

具有梯级释药性能的核壳型双重载药微球

分别利用单轴和同轴静电喷雾法成功制备出以聚乳酸-羟基乙酸共聚物（PLGA）为内核基质、聚乙烯吡咯烷酮（PVP）为外壳基质的核壳型双重载药微球,其中,抗菌药物盐酸万古霉素（VA）被包封于微球外壳,促成骨药物地塞米松（DA）被负载于微球内核。对载药微球的形貌结构、物理性质和体外释药性能进行了表征和分析。结果表明,当电喷前体PVP浓度为80g/L时,单轴和同轴静电喷雾方法均可得到大小均一、球形良好的核壳型微球。X射线衍射（XRD）和差示扫描量热（DSC）结果表明,DA晶体被成功包封于核壳型微球后转变为无定形状态。基于PVP的水溶性和PLGA的缓慢降解特性,两种核壳型载药微球都实现了壳层VA快速释放、内核DA缓慢释放的梯级释药性能。本文制备得到的具有梯级释药性能的核壳型载药微球在药物控释、组织工程等领域有很好的应用前景。     

Fabrication of porous scaffolds with a controllable microstructure and mechanical properties by porogen fusion technique

Macroporous scaffolds with controllable pore structure and mechanical properties were fabricated by a porogen fusion technique. Biodegradable material poly (d, l-lactide) (PDLLA) was used as the scaffold matrix. The effects of porogen size, PDLLA concentration and hydroxyapatite (HA) content on the scaffold morphology, porosity and mechanical properties were investigated. High porosity (90% and above) and highly interconnected structures were easily obtained and the pore size could be adjusted by varying the porogen size. With the increasing porogen size and PDLLA concentration, the porosity of scaffolds decreases, while its mechanical properties increase. The introduction of HA greatly increases the impact on pore structure, mechanical properties and water absorption ability of scaffolds, while it has comparatively little influence on its porosity under low HA contents. These results show that by adjusting processing parameters, scaffolds could afford a controllable pore size, exhibit suitable pore structure and high porosity, as well as good mechanical properties, and may serve as an excellent substrate for bone tissue engineering.     

Hyaluronic Acid and a Short Peptide Improve the Performance of a PCL Electrospun Fibrous Scaffold Designed for Bone Tissue Engineering Applications

Bone tissue engineering is a rapidly developing, minimally invasive technique for regenerating lost bone with the aid of biomaterial scaffolds that mimic the structure and function of the extracellular matrix (ECM). Recently, scaffolds made of electrospun fibers have aroused interest due to their similarity to the ECM, and high porosity. Hyaluronic acid (HA) is an abundant component of the ECM and an attractive material for use in regenerative medicine; however, its processability by electrospinning is poor, and it must be used in combination with another polymer. Here, we used electrospinning to fabricate a composite scaffold with a core/shell morphology composed of polycaprolactone (PCL) polymer and HA and incorporating a short self-assembling peptide. The peptide includes the arginine-glycine-aspartic acid (RGD) motif and supports cellular attachment based on molecular recognition. Electron microscopy imaging demonstrated that the fibrous network of the scaffold resembles the ECM structure. In vitro biocompatibility assays revealed that MC3T3-E1 preosteoblasts adhered well to the scaffold and proliferated, with significant osteogenic differentiation and calcium mineralization. Our work emphasizes the potential of this multi-component approach by which electrospinning, molecular self-assembly, and molecular recognition motifs are combined, to generate a leading candidate to serve as a scaffold for bone tissue engineering.     

Freeze-cast composite scaffolds prepared from sol-gel derived 58S bioactive glass and polycaprolactone

This work deals with the preparation of freeze-cast scaffolds using sol-gel derived 58S bioactive glass and a hypoeutectic naphthalene-camphor mixture as the starting powder and freezing vehicle, respectively. After the freeze-casting step, samples were air sintered at 1250?°C for 2?h, which led to the crystallization of 58S. The obtained scaffolds were subsequently infiltrated with poly(ε-caprolactone) (PCL), a biodegradable polymer with potential application for bone tissue repair. The prepared materials were examined by helium pycnometry, laser granulometry, scanning electron microscopy (SEM), Archimedes tests, X-ray microtomography (micro-CT), Fourier transform infrared spectroscopy (FTIR), N₂ adsorption, X-ray diffraction (XRD), and uniaxial compression tests. Samples cytotoxicity was evaluated by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction (MTT) and LIVE/DEAD assays. Their biocompatibility was also examined after soaking in a simulated body fluid (SBF) solution at 37?°C for up to 14 days. It was observed that the infiltration of PCL into the 58S scaffolds greatly increased their mechanical stability. Moreover, it was shown that these composites displayed a high cell viability (above 70%), which reveals that they did not interfere in the production of osteoblast cells. A hydroxyapatite coating was observed on the samples surface upon soaking in SBF, reinforcing that they are biocompatible materials. As far as we know, this is the first time that freeze-cast scaffolds were obtained using sol-gel derived 58S particles and a naphthalene-camphor mixture. Besides, as the infiltration of PCL into freeze-cast bioactive glass scaffolds improved their mechanical stability without impairing their bioactivity, this is a promising approach to prepare samples for load-bearing applications in bone tissue engineering.     

Facile synthesis of silica/polymer hybrid microspheres and hollow polymer microspheres

Monodisperse silica/polydivinylbenzene (SiO₂/PDVB) and silica/poly(ethyleneglycol dimethacrylate) (SiO₂/PEGDMA) core-shell hybrid microspheres were prepared by a two-stage reaction with silica particles' grafting of 3-(methacryloxy)propyltrimethoxysilane (MPS) as core and PDVB or PEGDMA as shell, in which the MPS-modified silica core with diameter of 238 nm was synthesized by Stöber method and subsequently grafted with MPS as the first-stage reaction. The PDVB or PEGDMA shell was then encapsulated over the MPS-modified silica core by distillation precipitation polymerization of divinylbenzene (DVB) or ethyleneglycol dimethacrylate (EGDMA) in neat acetonitrile with 2,2′-azobisisobutyronitrile (AIBN) initiator as the second-stage reaction. The encapsulation of PDVB and PEGDMA on modified silica core particles was driven by the capture of DVB or EGDMA oligomer radicals via the vinyl groups on the surface of the modified silica cores during the second-stage polymerization in the absence of any stabilizer or surfactant. The shell thickness of the core-shell hybrid particles was controlled by the feed of DVB or EGDMA monomer during the polymerization. Hollow PDVB or PEGDMA microspheres with various shell thickness were further developed after selective removal of the modified silica cores with hydrofluoric acid. The resultant core-shell hybrid materials and hollow microspheres were characterized by transmission electron microscopy (TEM), and Fourier transform infrared spectra (FT-IR).