Monodispersed Bioactive Glass Nanoparticles Enhance the Osteogenic Differentiation of Adipose‐Derived Stem Cells through Activating TGF‐Beta/Smad3 Signaling Pathway

It is important to understand the interaction mechanisms between nanomaterials and adipose‐derived stem cells for biomedical application. Nanoscale bioactive glass has positive effects on guiding osteoblasts differentiation and bone regeneration. However, the effects and molecular mechanism of monodispersed bioactive glass nanoparticles on the osteogenic differentiation of adipose‐derived stem cells are still not clear up to now. In this study, the effects and underlying molecular mechanism of monodispersed bioactive glass nanoparticles on the osteogenic differentiation of adipose‐derived stem cells are investigated in minute detail. The results show that nanoparticles (100–200 nm) can be absorbed by stem cells and is distributed in cytoplasm and nucleus. In both culture conditions (normal and osteoinductive), nanoparticles (80 µg mL⁻¹) can significantly enhance the osteogenic differentiation of stem cells through upregulating the alkaline phosphatase activity, osteogenic genes and protein expressions, as well as calcium deposition. Further study suggests that the activation of transforming growth factor‐beta/Smad3 signaling pathway plays an important role in the osteogenic differentiation of adipose‐derived stem cells enhanced by monodispersed nanoparticles. This study may have important implications for better understanding of stem cells fate induced by monodispersed nanoparticles and provide a promising approach toward stem cells‐based bone regeneration.     

Monodispersed β-Glycerophosphate-Decorated Bioactive Glass Nanoparticles Reinforce Osteogenic Differentiation of Adipose Stem Cells and Bone Regeneration In Vivo

Design and development of highly bioactive nanoscale biomaterials with enhanced osteogenic differentiation on adipose stem cells is rather important for bone regeneration and attracting much attention. Herein, monodispersed glycerophosphate-decorated bioactive glass nanoparticles (BGN@GP) are designed and their effect is investigated on the osteogenic differentiation of adipose mesenchymal stem cells (ADMSCs) and in vivo bone regeneration. The surface-modified BGN@GP can be efficiently taken by ADMSCs and shows negligible cytotoxicity. The in vitro results reveal that BGN@GP significantly enhances the alkaline phosphatase activity and calcium biominerialization of ADMSCs either under normal or osteoinductive medium as compared to BGNs. Further studies find that the osteogenic genes and proteins including Runx2 and Bsp in ADMSCs are significantly improved by BGN@GP even under normal culture medium. The in vivo animal experiment confirms that BGN@GP significantly promotes the new bone formation in a rat skull defect model. This study suggests that bioactive small molecule decorating is an efficient strategy to improve the osteogenesis capacity of inorganic ceramics nanomaterials.     

Protein‐Affinitive Polydopamine Nanoparticles as an Efficient Surface Modification Strategy for Versatile Porous Scaffolds Enhancing Tissue Regeneration

Porous scaffolds for tissue regeneration are often functionalized with extracellular matrix proteins to enhance surface/cell interactions and tissue regeneration. However, continuous coatings produced by commonly used surface modification strategies may preclude cells from contacting and sensing the chemical and physical cues of the scaffold. Here, it is shown that polydopamine nanoparticles (PDA‐NPs) tightly adhere on various scaffolds to form nanostructures, and the coverage can be finely tuned. Furthermore, the PDA‐NPs have good affinity to a variety of proteins and peptides. Thus, the PDA‐NPs act as an anchor to immobilize signal biomolecules on scaffolds, and consequently promote cell activity and tissue regeneration. β‐Tricalcium phosphate (TCP) scaffolds decorated with PDA‐NPs demonstrate excellent osteoinductivity and bone‐regeneration performance due to the protein affinity of PDA‐NPs and the intrinsic bioactive characteristics of TCP scaffolds. In summary, PDA‐NPs with excellent affinity for protein adhesion represent a versatile platform to modify porous scaffolds while not compromising the biological functions of the scaffolds, and might have potential applications in tissue regeneration.     

Facile Synthesis of Mg2+‐Doped Carbon Dots as Novel Biomaterial Inducing Cell Osteoblastic Differentiation

Carbon dots (CDs), as an emerging fluorescent nanomaterial with low toxicity, has been widely applied in various bio‐related fields. However, investigations on their capabilities in guiding osteogenic differentiation are rarely seen, which has great significance in osteoporosis therapy and bone regeneration. Herein, for the first time, a new kind of Mg²⁺‐doped CDs is facilely synthesized through a one‐step hydrothermal method from metal gluconate salts. The CDs can serve as nanocarrier of Mg²⁺ ions entering into cells, and the bioessential metal ions subsequently stimulate osteoblastic differentiation by improving alkaline phosphatase (ALP) activity and upregulation related mRNA expression. Noteworthy, the raw material has almost negligible performance on osteoblastic differentiation compared to Mg‐CDs, which is due to the ultrasmall sizes of CDs and the efficient uptake by cells. Moreover, benefitting from the fluorescence properties, Mg‐CDs can also be applied as cell labeling agents. This work proposes a new strategy to synthesize multifunctional metal ion‐doped CDs, which might had great potential in serving as promising nanodrugs for bone loss therapy.     

Enhanced Physiological Stability and Long‐Term Toxicity/Biodegradation In Vitro/In Vivo of Monodispersed Glycerolphosphate‐Functionalized Bioactive Glass Nanoparticles

Monodispersed bioactive glass nanoparticles (BGNs) have received much attention in various biomedical applications such as tissue regeneration, drug/gene delivery, bioimaging, and cancer therapy. However, the poor dispersion stability of BGNs in a physiological environment has limited their wide biomedical applications. The long‐term in vitro/in vivo toxicity and biodegradation of BGNs are also not clear. Monodispersed glycerolphosphate‐functionalized BGNs (GP‐BGN) are synthesized and their stability under physiological environment in vitro, and long‐term biodegradation behavior in vitro and in vivo are investigated herein. GP‐BGN shows significantly enhanced particles stability in physiological environment, good hemocompatibility and cellular biocompatibility, as well as high cellular uptake ability. GP‐BGN also exhibits long‐term biodegradation behavior in vitro/in vivo and negligible biotoxicity (tissue and blood toxicity). This study demonstrates that monodispersed surface‐functionalized BGNs could be used as biocompatible and biodegradable nanomaterials for long‐term safe bioimaging and disease therapy.     

Graphene and Graphene‐Based Materials in Biomedical Science

Graphene and its composite materials are very important in many disciplines of science and have been used enormously by researchers since their discovery in 2004. These are a new group of compounds, and are also wonderful model systems for quantum behavior studies. Their properties like exceptional conductivity, biocompatibility, surface area, mechanical strength, and thermal properties make them rising stars in the scientific community. Graphene and its composite compounds are utilized widely in different medical applications, for example, biosensing of biological compounds responsible for disease development, bioimaging of various cells, tissues, microorganisms, animal models, etc. In addition, they are used for enhancing and supporting the stem cell differentiation, i.e., regenerative medicine for regeneration studies of various human organs, tissue engineering in biology for the development of carrier materials, as well as in bone reformation. This review focuses on the modification procedure involved in the fabrication of graphene‐based biomaterials for various applications and recent developments in research related to graphene and graphene‐based materials in biosensing, optical sensing, gas sensing, drug, gene, protein delivery, tissue engineering, and bioimaging. In addition, the potential toxicological effects of graphene‐based biomaterials are discussed.     

Incorporation of Boron in Mesoporous Bioactive Glass Nanoparticles Reduces Inflammatory Response and Delays Osteogenic Differentiation

Mesoporous bioactive glass nanoparticles (MBG) are multifunctional building blocks for tissue regeneration and nanomedicine applications. Incorporation of biologically active ions can endow MBG with additional functionalities toward promoted therapeutic effects. Here, boron is incorporated into MBG by using a sol–gel approach. The concentration of boron incorporated is controllable by tuning the amount of boron precursor. Two types of boron-doped MBG, namely 10B- and 15B-MBG (5.8 and 6.5 mol% of B₂O₃, respectively) are synthesized. Boron incorporation does not significantly influence the particle morphology. All synthesized particles exhibit a sphere-like shape with a size ranging from 100 to 300 nm. 10B- and 15B-MBG show large specific surface area (346 and 320 m² g⁻¹, respectively) and pore volume. Both boron-doped MBG exhibit remarkable in vitro bioactivity and noncytotoxicity. Boron incorporation is shown to reduce the inflammatory response linked to macrophages as indicated by downregulated expression of pro-inflammatory genes. However, boron incorporation delays the osteogenic differentiation in osteoblasts as indicated by the downregulated expression of pro-osteogenic genes. The results demonstrate the promising potential of using boron-doped MBG to modulate inflammatory response for bone regeneration under inflammatory conditions, as shown in this study for the first time.     

In vivo bone regeneration using a novel porous bioactive composite

Many commercial bone graft substitutes (BGS) and experimental bone tissue engineering scaffolds have been developed for bone repair and regeneration. This study reports the in vivo bone regeneration using a newly developed porous bioactive and resorbable composite that is composed of bioactive glass (BG), collagen (COL), hyaluronic acid (HYA) and phosphatidylserine (PS), BG-COL-HYA-PS. The composite was prepared by a combination of sol-gel and freeze-drying methods. A rabbit radius defect model was used to evaluate bone regeneration at time points of 2, 4 and 8 weeks. Techniques including radiography, histology, and micro-CT were applied to characterize the new bone formation. 8 weeks results showed that (1) nearly complete bone regeneration was achieved for the BG-COL-HYA-PS composite that was combined with a bovine bone morphogenetic protein (BMP); (2) partial bone regeneration was achieved for the BG-COL-HYA-PS composites alone; and (3) control remained empty. This study demonstrated that the novel BG-COL-HYA-PS, with or without the grafting of BMP incorporation, is a promising BGS or a tissue engineering scaffold for non-load bearing orthopaedic applications.     

Fibrin-based matrix for stem cell isolation and as a basis for new technologies for tissue regeneration

Fibrin microbeads (FMB) are made by moderate-heat condensation of fibrin drops in oil to obtain beads in the range of 100–200 μm. This procedure yields protein-based hard stable beads with high binding capability of the matrix dependent cell. Therefore, the FMB could serve for high yield isolation of mesenchymal stem cells (MSC) from different sources in higher yield than that obtained by conventional methods. The cells could be expanded on the FMB in suspension culture without the need for trypsinization and passages. Cell differentiation into different phenotypes, such as bone and cartilage, can be induced in cells loaded on FMB. When implanted, the cells on FMB survive the implantation and can download to become integrated with the target organs for tissue regeneration. This makes the use of FMB a simple technique for cell-based tissue regeneration without the need for implanting bulk scaffolds on which the cells have a low rate of survival. FMB technology provides a simple and highly effective fibrin-based method for cell separation, expansion in suspension and delivery to assist tissue regeneration.     

Characterisation of cryopreserved cells freshly isolated from human bone marrow

Osteoblast progenitor cells (OBPCs) isolated from bone marrow have the ability to differentiate into osteoblasts and thus potential therapeutic use to tissue-engineer bone. In order for OBPCs to be available for clinical use a means of storing viable cells is necessary. The aim of this study was to determine whether a simple method of cryopreservation had an effect on osteogenic differentiation or growth of OBPCs isolated from fresh human bone marrow. Stro-1 was used to identify the isolated OBPCs. The osteoblastic potential of the marrow cells was confirmed as culture with osteogenic supplements (OS) significantly increased osteoblastic protein production (alkaline phosphatase (ALP), osteopontin and osteocalcin) compared with standard conditions (P less than 0.05). Ten further marrow aspirates were harvested; each was halved for either cryopreservation or control culture. Primary cultures from both populations formed colonies with recognised OBPC morphology. OS stimulated both cryopreserved and control populations to produce significantly more osteoblastic proteins (P less than 0.05) and there was no significant difference between the increase in osteogenic proteins when cultured with OS (P great than 0.2). The proliferation rate after 5 days in culture was not significantly affected by cryopreservation (P greater than 0.05). It has been suggested that OBPCs are immuno-privileged; so allogenic cells could be implanted into patients for tissue engineering bone without causing a hypersensitivity reaction. Our study demonstrates a method of storage, which allows OBPCs to be available for use without affecting osteoblastic potential or viability.     

Cell differentiation modeled via a coupled two-switch regulatory network

Mesenchymal stem cells can give rise to bone and other tissue cells, but their differentiation still escapes full control. In this paper we address this issue by mathematical modeling. We present a model for a genetic switch determining the cell fate of progenitor cells which can differentiate into osteoblasts (bone cells) or chondrocytes (cartilage cells). The model consists of two switch mechanisms and reproduces the experimentally observed three stable equilibrium states: a progenitor, an osteogenic, and a chondrogenic state. Conventionally, the loss of an intermediate (progenitor) state and the entailed attraction to one of two opposite (differentiated) states is modeled as a result of changing parameters. In our model in contrast, we achieve this by distributing the differentiation process to two functional switch parts acting in concert: one triggering differentiation and the other determining cell fate. Via stability and bifurcation analysis, we investigate the effects of biochemical stimuli associated with different system inputs. We employ our model to generate differentiation scenarios on the single cell as well as on the cell population level. The single cell scenarios allow to reconstruct the switching upon extrinsic signals, whereas the cell population scenarios provide a framework to identify the impact of intrinsic properties and the limiting factors for successful differentiation.     

Development of poly(butylene succinate)/calcium phosphate composites for bone engineering

Bone tissue engineering offers the prospect of alternative therapies for clinically relevant skeletal defects. Poly(butylene succinate) (PBSu) is a biodegradable and biocompatible polyester which possesses some unfavorable biomaterial properties. In order to improve this limitation, we developed PBSu/hydroxyapatite (HA) and PBSu/β-tricalcium phosphate (TCP) composites to support the growth and osteogenic differentiation of human mesenchymal stem cells (hMSCs). The results showed that phase separation morphology of the composites were detected in both PBSu/HA and PBSu/TCP films where calcium phosphate (HA and TCP) dispersed thoroughly into PBSu. The addition of either HA or TCP increased the hydrophilicity of the resulting composites. All the materials appeared to be biocompatible and supported in vitro growth and osteoblast differentiation of hMSCs. In conclusion, the currently developed composite materials possess good biocompatibility and allow the growth and osteogenic differentiation of hMSCs in vitro, suggesting their potential application in stem cell-based bone engineering.     

Biomimetic formation of apatite on the surface of porous gelatin/bioactive glass nanocomposite scaffolds

There have been several attempts to combine bioactive glasses (BaGs) with biodegradable polymers to create a scaffold material with excellent biocompatibility, bioactivity, biodegradability and toughness. In the present study, the nanocomposite scaffolds with compositions based on gelatin (Gel) and BaG nanoparticles in the ternary SiO₂-CaO-P₂O₅ system were prepared. In vitro evaluations of the nanocomposite scaffolds were performed, and for investigating their bioactive capacity these scaffolds were soaked in a simulated body fluid (SBF) at different time intervals. The scaffolds showed significant enhancement in bioactivity within few days of immersion in SBF solution. The apatite formation at the surface of the nanocomposite samples confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray powder diffraction (XRD) analyses. In vitro experiments with osteoblast cells indicated an appropriate penetration of the cells into the scaffold's pores, and also the continuous increase in cell aggregation on the bioactive scaffolds with increase in the incubation time demonstrated the ability of the scaffolds to support cell growth. The SEM observations revealed that the prepared scaffolds were porous with three dimensional (3D) and interconnected microstructure, pore size was 200-500 μm and the porosity was 72-86%. The nanocomposite scaffold made from Gel and BaG nanoparticles could be considered as a highly bioactive and potential bone tissue engineering implant.     

Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH₂ of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.     

In vitro evaluation of osteoblast‐like cells on hydroxyapatite‐coated porous stainless steel implants by synchrotron radiation x‐ray fluorescence

The successful application of artificial implants requires osseointegration in the implanted structures. To stimulate bone growth, synthetic hydroxyapatite obtained by the coprecipitation process was coated onto porous stainless steel substrates in order to enhance the biocompatibility and, consequently, mineralization. The substrate of choice was porous 316L stainless steel for its high resistance, mechanical strength and low density due to its foam structure. The aim of the present study was to investigate the biological response of the fabricated implants cultured with MC3T3‐E1 mouse osteoblast‐like cells by analyzing the variation in the elemental concentration, mainly calcium, along with the cellular differentiation and mineralization. By employing synchrotron radiation x‐ray fluorescence spectroscopy (SRXRF), intracellular elemental distribution and concentration could be determined, revealing a clear increase in the total calcium content. This preliminary data suggests that synthetic hydroxyapatite on porous stainless steel substrates might be successfully used for biocompatible medical implants. Copyright © 2009 John Wiley & Sons, Ltd.     

Probing electronic structure of biomineralized hydroxyapatite inside nanoclay galleries

Hydroxyapatite, the most abundant mineral in the human body, is also an important component in design of biomaterials for bone tissue regeneration. Synthetic hydroxyapatite mineralized in the laboratory often does not exhibit the same biological and morphological properties of biogenic hydroxyapatite in human bone. A biomimetic hydroxyapatite structure is synthesized using biomineralization routes inside the clay galleries of montmorillonite clay. Amino acids are used to modify the clay galleries. These amino acids are used to mineralize hydroxyapatite. The molecular interactions between nanoclay, modifiers inside nanoclay (amino acids) and biomineralized hydroxyapatite result in unique morphology, structure and stoichiometry of the biomineralized hydroxyapatite. Prior studies have indicated that this biomineralized hydroxyapatite inside nanoclay galleries is an effective component of tissue engineering bone scaffolds that elicits an optimal biological response from human mesenchymal stem cells. Here, a detailed electron energy-loss spectroscopy (EELS) study is reported that elucidates the differences in hydroxyapatite, biomineralized hydroxyapatite and β-tricalcium phosphate (β-TCP). Comparison of EELS low-loss transitions and energy loss near-edge structure (ELNES) of P-L_2,3 edges for these three compounds is done to determine if there are differences in their electronic structures. These changes observed experimentally are compared with prior predictions and simulations using molecular dynamics studies. The simulations predict attractive and repulsive interactions between phosphate, modified MMT clay and aminovaleric acid (amino acid) molecules. Kramers-Kronig analysis is performed on the loss spectra obtained to yield the real and imaginary parts of the dielectric function of the apatites (ε₁ and ε ₂). We have also used the ε₂ spectra obtained to calculate the AC conductivity spectra for the apatites. This study represents a unique experimental probe into molecular interactions in complex biomineralized hydroxyapatite structures. The small changes observed in the energy loss spectra appear to play important biological roles in biomineralized hydroxyapatite such as the ability to differentiate human mesenchymal stem cells into osteoblasts without growth media.     

Synthesis of Porous NiO Nanorods as High‐Performance Anode Materials for Lithium‐Ion Batteries

1D nanostructured metal oxides with porous structure have drawn wide attention to being used as high‐performance anode materials for lithium‐ion batteries (LIBs). This study puts forward a simple and scalable strategy to synthesize porous NiO nanorods with the help of a thermal treatment of metal‐organic frameworks in air. The NiO nanorods with an average diameter of approximately 38 nm are composed of nanosized primary particles. When evaluated as anode materials for LIBs, an initial discharge capacity of 743 mA h g^?1 is obtained at a current density of 100 mA g^?1, and a high reversible capacity is still maintained as high as 700 mA h g^?1 even after 60 charge–discharge cycles. The excellent electrochemical performance is mainly ascribed to the 1D porous structure.     

Effect of gold nanoparticles on adipogenic differentiation of human mesenchymal stem cells

Gold nanoparticles are very attractive for biomedical products. However, there is a serious lack of information concerning the biological activity of nanosized gold in human tissue cells. An influence of nanoparticles on stem cells might lead to unforeseen consequences to organ and tissue functions as long as all cells arising from the initial stem cell might be subsequently damaged. Therefore the effect of negatively charged gold nanoparticles (9 and 95 nm), which are certified as reference material for preclinical biomedical research, on the adipogenic differentiation of human mesenchymal stem cells (hMSCs) is investigated here. Bone marrow hMSCs are chosen as differentiation model since bone marrow hMSCs are well characterized and their differentiation into the adipogenic lineage shows clear and easily detectable differentiation. In this study effects of gold nanoparticles on adipogenic differentiation are analyzed regarding fat storage and mitochondrial activity after different exposure times (4–21 days). Using time lapse microscopy the differentiation progress under chronically gold nanoparticle treatment is continuously investigated. In this preliminary study, chronically treatment of adipogenic differentiating hMSCs with gold nanoparticles resulted in a reduced number and size of lipid vacuoles and reduced mitochondrial activity depending on the applied concentration and the surface charge of the particles.     

Nano‐in‐Micro POxylated Polyurea Dendrimers and Chitosan Dry Powder Formulations for Pulmonary Delivery

Pulmonary administration offers excellent advantages over conventional drug delivery routes, including increasing therapeutics bioavailability, and avoiding long‐term safety issues. Formulations of nano‐in‐micro dry powders for lung delivery are engineered using (S)‐ibuprofen as a model drug. These biodegradable formulations comprise nanoparticles of drug‐loaded POxylated polyurea dendrimers coated with chitosan using supercritical‐fluid‐assisted spray drying. The formulations are characterized in terms of morphology, particle‐size distribution, in vitro aerodynamic particle pulmonary distribution, and glutathione‐S‐transferase assay. It is demonstrated that ibuprofen‐loaded nanoparticles can be successfully incorporated into microspheres with adequate aerodynamic properties, mass median aerodynamic diameter (1.86–3.83 μm), and fine particle fraction (28%–45%), for deposition into the deep lung. The (S)‐ibuprofen dry powder formulations show enhanced solubility, high swelling behavior and a sustained drug release at physiologic pH. Also, POxylated polyureas decrease the (S)‐ibuprofen toxic effect on cancer cellular growth. The 3‐(4,5‐dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2H‐tetrazolium (MTS) assays show no significant cytotoxicity on the metabolic activity of human lung adenocarcinoma ephithelial (A549) cell line for the lowest concentration (1 × 10^?3 m ), even for longer periods of contact with the cells (up to 120 h), and in the normal human dermal fibroblasts cell line the toxic effect is also reduced.     

A Simple,Scalable Process for the Production of Porous Polymer Microspheres by Ink‐Jetting Combined with Thermally Induced Phase Separation

Porous microspheres capable of delivering high payloads of biomolecules with suitable biodegradability and biocompatibility would be valuable in delivery systems to aid tissue regeneration. This study describes a facile, scalable technique to produce biodegradable porous microspheres by combining continuous ink‐jetting through a piezoelectric nozzle with thermally induced phase separation (TIPS). A selection of biomaterials is investigated to suit delivery in tissue engineering, the synthetic polyesters poly(lactic‐co‐glycolic acid) (PLGA), and poly caprolactone (PCL) and a natural polymer, gelatin. The parameters governing the microsphere production are determined experimentally and compared to theoretical predictions derived from the fluid mechanics and heat transfer during the ink‐jetting process. The microspheres produced have open interconnected pores with mean particle diameters of 80–200 μm and no significant skin region. The physical properties, such as the mean particle diameter, pore size, and surface area could be controlled by varying production parameters including the ink‐jetting pressure, nozzle height, and the size and oscillation frequency of the nozzle. The technique is demonstrated to successfully encapsulate a model hydrophobic molecule during microsphere production with uniform distribution. Porous PLGA microspheres are also used to achieve much higher adsorption capacities of a short peptide than non‐porous microspheres of the same material.