Soybean Lecithin‐Mediated Nanoporous PLGA Microspheres with Highly Entrapped and Controlled Released BMP‐2 as a Stem Cell Platform

Injectable polymer microsphere‐based stem cell delivery systems have a severe problem that they do not offer a desirable environment for stem cell adhesion, proliferation, and differentiation because it is difficult to entrap a large number of hydrophilic functional protein molecules into the core of hydrophobic polymer microspheres. In this work, soybean lecithin (SL) is applied to entrap hydrophilic bone morphogenic protein‐2 (BMP‐2) into nanoporous poly(lactide‐co‐glycolide) (PLGA)‐based microspheres by a two‐step method: SL/BMP‐2 complexes preparation and PLGA/SL/BMP‐2 microsphere preparation. The measurements of their physicochemical properties show that PLGA/SL/BMP‐2 microspheres had significantly higher BMP‐2 entrapment efficiency and controlled triphasic BMP‐2 release behavior compared with PLGA/BMP‐2 microspheres. Furthermore, the in vitro and in vivo stem cell behaviors on PLGA/SL/BMP‐2 microspheres are analyzed. Compared with PLGA/BMP‐2 microspheres, PLGA/SL/BMP‐2 microspheres have significantly higher in vitro and in vivo stem cell attachment, proliferation, differentiation, and matrix mineralization abilities. Therefore, injectable nanoporous PLGA/SL/BMP‐2 microspheres can be potentially used as a stem cell platform for bone tissue regeneration. In addition, SL can be potentially used to prepare hydrophilic protein‐loaded hydrophobic polymer microspheres with highly entrapped and controlled release of proteins.     

Injectable and Crosslinkable PLGA‐Based Microribbons as 3D Macroporous Stem Cell Niche

Poly(lactide‐co‐glycolide) (PLGA) has been widely used as a tissue engineering scaffold. However, conventional PLGA scaffolds are not injectable, and do not support direct cell encapsulation, leading to poor cell distribution in 3D. Here, a method for fabricating injectable and intercrosslinkable PLGA microribbon‐based macroporous scaffolds as 3D stem cell niche is reported. PLGA is first fabricated into microribbon‐shape building blocks with tunable width using microcontact printing, then coated with fibrinogen to enhance solubility and injectability using aqueous solution. Upon mixing with thrombin, firbornogen‐coated PLGA microribbons can intercrosslink into 3D scaffolds. When subject to cyclic compression, PLGA microribbon scaffolds exhibit great shock‐absorbing capacity and return to their original shape, while conventional PLGA scaffolds exhibit permanent deformation after one cycle. Using human mesenchymal stem cells (hMSCs) as a model cell type, it is demonstrated that PLGA μRB scaffolds support homogeneous cell encapsulation, and robust cell spreading and proliferation in 3D. After 28 days of culture in osteogenic medium, hMSC‐seeded PLGA μRB scaffolds exhibit an increase in compressive modulus and robust bone formation as shown by staining of alkaline phosphatase, mineralization, and collagen. Together, the results validate PLGA μRBs as a promising injectable, macroporous, non‐hydrogel‐based scaffold for cell delivery and tissue regeneration applications.     

Synthesis and Assembly of Click‐Nucleic‐Acid‐Containing PEG–PLGA Nanoparticles for DNA Delivery

Co‐delivery of both chemotherapy drugs and siRNA from a single delivery vehicle can have a significant impact on cancer therapy due to the potential for overcoming issues such as drug resistance. However, the inherent chemical differences between charged nucleic acids and hydrophobic drugs have hindered entrapment of both components within a single carrier. While poly(ethylene glycol)‐block‐poly(lactic‐co‐glycolic acid) (PEG–PLGA) copolymers have been used successfully for targeted delivery of chemotherapy drugs, loading of DNA or RNA has been poor. It is demonstrated that significant amounts of DNA can be encapsulated within PLGA‐containing nanoparticles through the use of a new synthetic DNA analog, click nucleic acids (CNAs). First, triblock copolymers of PEG‐CNA‐PLGA are synthesized and then formulated into polymer nanoparticles from oil‐in‐water emulsions. The CNA‐containing particles show high encapsulation of DNA complementary to the CNA sequence, whereas PEG‐PLGA alone shows minimal DNA loading, and non‐complementary DNA strands do not get encapsulated within the PEG‐CNA‐PLGA nanoparticles. Furthermore, the dye pyrene can be successfully co‐loaded with DNA and lastly, a complex, larger DNA sequence that contains an overhang complementary to the CNA can also be encapsulated, demonstrating the potential utility of the CNA‐containing particles as carriers for chemotherapy agents and gene silencers.     

Mussel Adhesion‐Inspired Reverse Transfection Platform Enhances Osteogenic Differentiation and Bone Formation of Human Adipose‐Derived Stem Cells

Using small interfering RNA (siRNA) to regulate gene expression is an emerging strategy for stem cell manipulation to improve stem cell therapy. However, conventional methods of siRNA delivery into stem cells based on solution‐mediated transfection are limited due to low transfection efficiency and insufficient duration of cell‐siRNA contact during lengthy culturing protocols. To overcome these limitations, a bio‐inspired polymer‐mediated reverse transfection system is developed consisting of implantable poly(lactic‐co‐glycolic acid) (PLGA) scaffolds functionalized with siRNA‐lipidoid nanoparticle (sLNP) complexes via polydopamine (pDA) coating. Immobilized sLNP complexes are stably maintained without any loss of siRNA on the pDA‐coated scaffolds for 2 weeks, likely due to the formation of strong covalent bonds between amine groups of sLNP and catechol group of pDA. siRNA reverse transfection with the pDA‐sLNP‐PLGA system does not exhibit cytotoxicity and induces efficient silencing of an osteogenesis inhibitor gene in human adipose‐derived stem cells (hADSCs), resulting in enhanced osteogenic differentiation of hADSCs. Finally, hADSCs osteogenically committed on the pDA‐sLNP‐PLGA scaffolds enhanced bone formation in a mouse model of critical‐sized bone defect. Therefore, the bio‐inspired reverse transfection system can provide an all‐in‐one platform for genetic modification, differentiation, and transplantation of stem cells, simultaneously enabling both stem cell manipulation and tissue engineering.     

In vitro evaluation of the effects of various additives and polymers on nerve growth factor microspheres

Objective: To evaluate the effects of various additives or polymers on the in vitro characteristics of nerve growth factor (NGF) microspheres.

Materials and methods: NGF microspheres were fabricated using polyethylene glycol (PEG), ovalbumin (OVA), bovine serum albumin (BSA) or glucose as protein protectors, and poly(lactide-co-glycolide) (PLGA) or poly(lactic acid) (PLA)/PLGA blends as encapsulation materials.

Results: Encapsulation efficiencies of the NGF microspheres with various additives or polymers were not more than 30%. A comparative study revealed that OVA was somewhat superior over others, and was thus chosen as the protective additive in subsequent experiments. Polymer analysis showed that NGF release from 1:1 PLA (η?=?0.8):PLGA (75/25, η?=?0.45) microspheres lasted for 90?d with a burst release rate of 12.7%. About 40% of the original bioactivity was retained on the 28th day, while 10% was left on the 90th day.

Discussion and conclusion: The combination of OVA as an additive and the PLA/PLGA blend as the coating matrix is suitable for encapsulation of NGF in microspheres for extended release.     

Tunable Photonic Microspheres of Comb‐Like Supramolecules

Photonic crystals (PCs) are ideal candidates for reflective color pigments with high color purity and brightness due to tunable optical stop band. Herein, the generation of PC microspheres through 3D confined supramolecular assembly of block copolymers (polystyrene‐block‐poly(2‐vinylpyridine), PS‐b‐P2VP) and small molecules (3‐n‐pentadecylphenol, PDP) in emulsion droplets is demonstrated. The intrinsic structural colors of the PC microspheres are effectively regulated by tuning hydrogen‐bonding interaction between P2VP blocks and PDP, where reflected color can be readily tuned across the whole visible spectrum range. Also, the effects of both PDP and homopolymer (hPS) on periodic structure and optical properties of the microspheres are investigated. Moreover, the spectral results of finite element method (FEM) simulation agree well with the variation of structural colors by tuning the periodicity in PC microspheres. The supramolecular microspheres with tunable intrinsic structural color can be potentially useful in the various practical applications including display, anti‐counterfeit printing and painting.     

Eccentric Loading of Fluorogen with Aggregation‐Induced Emission in PLGA Matrix Increases Nanoparticle Fluorescence Quantum Yield for Targeted Cellular Imaging

A simple strategy is developed to prepare eccentrically or homogeneously loaded nanoparticles (NPs) using poly (DL‐lactide‐co‐glycolide) (PLGA) as the encapsulation matrix in the presence of different amounts of polyvinyl alcohol (PVA) as the emulsifier. Using 2,3‐bis(4‐(phenyl(4‐(1,2,2‐triphenylvinyl)‐phenyl)amino)‐phenyl)‐fumaronitrile (TPETPAFN), a fluorogen with aggregation‐induced emission (AIE) characteristics, as an example, the eccentrically loaded PLGA NPs show increased fluorescence quantum yields (QYs) as compared to the homogeneously loaded ones. Field emission transmission electron microscopy and fluorescence lifetime measurements reveal that the higher QY of the eccentrically loaded NPs is due to the more compact aggregation of AIE fluorogens that restricts intramolecular rotations of phenyl rings, which is able to more effectively block the non‐radiative decay pathways. The eccentrically loaded NPs show far red/near infrared emission with a high fluorescence QY of 34% in aqueous media. In addition, by using poly([lactide‐co‐glycolide]‐b‐folate [ethylene glycol]) (PLGA‐PEG‐folate) as the co‐encapsulation matrix, the obtained NPs are born with surface folic acid groups, which are successfully applied for targeted cellular imaging with good photostability and low cytotoxicity. Moreover, the developed strategy is also demonstrated for inorganic‐component eccentrically or homogeneously loaded PLGA NPs, which facilitates the synthesis of polymer NPs with controlled internal architectures.     

Mineralization of Collagen‐Coated Electrospun Poly(lactide‐co‐glycolide) Nanofibrous Mesh to Enhance Growth and Differentiation of Osteoblasts and Bone Marrow Mesenchymal Stem Cells

To obtain the biomimetic scaffolding materials for bone tissue engineering, poly(lactide‐co‐glycolide) (PLGA) nanofibrous mesh (NFM) was mineralized in a 5× simulated body fluid (SBF) for different time after it was treated by air plasma for 15 min and subsequent collagen coating. The apatite particles were nucleated on the surface of individual nanofibers, gradually grew up, and finally covered the whole NFM surface. The mineral aggregates were mainly composed of tiny hydroxyapatite (HA) nanoparticles, whose content reached a constant value of 54 µg · cm^?2 after 9 days. The collagen coating and apatite deposition enhanced the NFM strength pronouncedly too. In vitro cell culture demonstrated that the non‐ or less mineralized NFMs were more beneficial of cell spreading and proliferation than those highly mineralized NFMs, but the latter ones could strongly promote secretion of alkaline phosphatase (ALP) by osteoblasts after cultured for 14 days. Moreover, the highly mineralized NFMs also could significantly up‐regulated ALP activity and calcium synthesis of bone marrow mesenchymal stem cells (BMSCs), demonstrating that these NFMs are more favorable of the osteoblast phenotype expression and osteogenic induction. Therefore, the biomimetic apatite deposited PLGA/collagen NFM could be a promising candidate scaffold for bone tissue engineering.     

Inhibition of 3‐D Tumor Spheroids by Timed‐Released Hydrophilic and Hydrophobic Drugs from Multilayered Polymeric Microparticles

First‐line cancer chemotherapy necessitates high parenteral dosage and repeated dosing of a combination of drugs over a prolonged period. Current commercially available chemotherapeutic agents, such as Doxil and Taxol, are only capable of delivering single drug in a bolus dose. The aim of this study is to develop dual‐drug‐loaded, multilayered microparticles and to investigate their antitumor efficacy compared with single‐drug‐loaded particles. Results show hydrophilic doxorubicin HCl (DOX) and hydrophobic paclitaxel (PTX) localized in the poly(dl ‐lactic‐co‐glycolic acid, 50:50) (PLGA) shell and in the poly(l ‐lactic acid) (PLLA) core, respectively. The introduction of poly[(1,6‐bis‐carboxyphenoxy) hexane] (PCPH) into PLGA/PLLA microparticles causes PTX to be localized in the PLLA and PCPH mid‐layers, whereas DOX is found in both the PLGA shell and core. PLGA/PLLA/PCPH microparticles with denser shells allow better control of DOX release. A delayed release of PTX is observed with the addition of PCPH. Three‐dimensional MCF‐7 spheroid studies demonstrate that controlled co‐delivery of DOX and PTX from multilayered microparticles produces a greater reduction in spheroid growth rate compared with single‐drug‐loaded particles. This study provides mechanistic insights into how distinctive structure of multilayered microparticles can be designed to modulate the release profiles of anticancer drugs, and how co‐delivery can potentially provide better antitumor response.     

Self‐Adjusting,Polymeric Multilayered Roll that can Keep the Shapes of the Blood Vessel Scaffolds during Biodegradation

A self‐adjusting, blood vessel‐mimicking, multilayered tubular structure with two polymers, poly(ε‐caprolactone) (PCL) and poly(dl ‐lactide‐co‐glycolide) (PLGA), can keep the shape of the scaffold during biodegradation. The inner (PCL) layer of the tube can expand whereas the outer (PLGA) layers will shrink to maintain the stability of the shape and the inner space of the tubular shape both in vitro and in vivo over months. This approach can be generally useful for making scaffolds that require the maintenance of a defined shape, based on FDA‐approved materials.     

Fabrication and characterization of porous poly(lactic-<Emphasis Type="Italic">co</Emphasis>-glycolic acid) (PLGA) microspheres for use as a drug delivery system

In this work, Simvastatin (SIM) loaded porous poly(lactic-co-glycolic acid) (PLGA) microspheres were fabricated using the W/O/W1/W2 double emulsion and solvent evaporation method. The optimal conditions for fabricating porous PLGA microspheres were determined to be 20% distilled water (v/v), 10% PLGA (m/v), and a 4:1 ratio of internal polyvinyl alcohol (PVA) to dichloromethane (DCM). The pores size distribution of porous PLGA microspheres was varied from 0.01 to 40 μm, while their particle displayed a bimodal size distribution that had two diameter peaks at around 100 μm and 500 μm. The SIM encapsulation efficacy was found to be very high with a yield near 80% and the porous PLGA microspheres showed the excellent biocompatibility. In addition, the drug release profile was found to be significantly different from a temporal basis. Base on the combined results of this study, SIM loaded PLGA microspheres holds great promise for use in biomedical applications, especially in drug delivery system or tissue regeneration.     

Manufacture,Characterization, and Release Profiles of Insulin-Loaded Mesoporous PLGA Microspheres

This paper reports the fabrication of insulin-loaded mesoporous microspheres by a double emulsion-solvent evaporation technique using poly(lactic acid-co-glycolic acid) (PLGA) as carrier materials. PLGA solutions with two different concentrations (4% and 5%) were used as the oil phases to fabricate the mesoporous microspheres. The morphology and the particle size distribution of final microspheres were studied by optical microscope, scanning electronic microscope (SEM), and Malvern 2600 sizer, respectively. The mesoporous microspheres were monodisperse with an average diameter of 7 ± 3.5 µm. Insulin, as a model drug, was encapsulated into the final microspheres. In vitro release studies suggested that insulin was continuously released from the medicated microspheres. Furthermore, the final microspheres obtained from 4% PLGA solution showed a small “burst release” effect for their dense structures, which shortened the lag time to the effective plasma concentration. To summarize, the insulin-loaded PLGA microsphere are very promising for use in pharmaceutical applications.     

Physicochemical characterization of spray-dried PLGA/PEG microspheres,and preliminary assessment of biological response

Context: The use of spray-drying to prepare blended PLGA:PEG microspheres with lower immune detection.

Objective: To study physical properties, polymer miscibility and alveolar macrophage response for blended PLGA:PEG microspheres prepared by a laboratory-scale spray-drying process.

Methods: Microspheres were prepared by spray-drying 0–20% w/w ratios of PLGA 65:35 and PEG 3350 in dichloromethane. Particle size and morphology was studied using scanning electron microscopy. Polymer miscibility and residual solvent levels evaluated by thermal analysis (differential scanning calorimetry – DSC and thermogravimetric analysis – TGA). Immunogenicity was assessed in vitro by response of rat alveolar macrophages (NR8383) by the MTT-based cell viability assay and reactive oxygen species (ROS) detection.

Results: The spray dried particles were spherical, with a size range of about 2–3?µm and a yield of 16–60%. Highest yield was obtained at 1% PEG concentration. Thermal analysis showed a melting peak at 59?°C (enthalpy: 170.61 J/g) and a degradation-onset of 180?°C for PEG 3350. PLGA 65:35 was amorphous, with a T_g of 43?°C. Blended PLGA:PEG microspheres showed a delayed degradation-onset of 280?°C, and PEG enthalpy-loss corresponding to 15% miscibility of PEG in PLGA. NR8383 viability studies and ROS detection upon exposure to these cells suggested that blended PLGA:PEG microspheres containing 1 and 5% PEG are optimal in controling cell proliferation and activation.

Conclusion: This research establishes the feasibility of using a spray-drying process to prepare spherical particles (2–3?µm) of molecularly-blended PLGA 65:35 and PEG 3350. A PEG concentration of 1–5% was optimal to maximize process yield, with minimal potential for immune detection.     

Nanoparticle‐Enhanced Radiotherapy to Trigger Robust Cancer Immunotherapy

External radiotherapy is extensively used in clinic to destruct tumors by locally applied ionizing‐radiation beams. However, the efficacy of radiotherapy is usually limited by tumor hypoxia‐associated radiation resistance. Moreover, as a local treatment technique, radiotherapy can hardly control tumor metastases, the major cause of cancer death. Herein, core–shell nanoparticles based poly(lactic‐co‐glycolic) acid (PLGA) are fabricate, by encapsulating water‐soluble catalase (Cat), an enzyme that can decompose H₂O₂ to generate O₂, inside the inner core, and loading hydrophobic imiquimod (R837), a Toll‐like‐receptor‐7 agonist, within the PLGA shell. The formed PLGA‐R837@Cat nanoparticles can greatly enhance radiotherapy efficacy by relieving the tumor hypoxia and modulating the immune‐suppressive tumor microenvironment. The tumor‐associated antigens generated postradiotherapy‐induced immunogenic cell death in the presence of such R837‐loaded adjuvant nanoparticles will induce strong antitumor immune responses, which together with cytotoxic T‐lymphocyte associated protein 4 (CTLA‐4) checkpoint blockade will be able to effectively inhibit tumor metastases by a strong abscopal effect. Moreover, a long term immunological memory effect to protect mice from tumor rechallenging is observed post such treatment. This work thus presents a unique nanomedicine approach as a next‐generation radiotherapy strategy to enable synergistic whole‐body therapeutic responses after local treatment, greatly promising for clinical translation.     

Erythrocyte‐Membrane‐Enveloped Perfluorocarbon as Nanoscale Artificial Red Blood Cells to Relieve Tumor Hypoxia and Enhance Cancer Radiotherapy

Hypoxia, a common feature within many types of solid tumors, is known to be closely associated with limited efficacy for cancer therapies, including radiotherapy (RT) in which oxygen is essential to promote radiation‐induced cell damage. Here, an artificial nanoscale red‐blood‐cell system is designed by encapsulating perfluorocarbon (PFC), a commonly used artificial blood substitute, within biocompatible poly(d ,l ‐lactide‐co‐glycolide) (PLGA), obtaining PFC@PLGA nanoparticles, which are further coated with a red‐blood‐cell membrane (RBCM). The developed PFC@PLGA‐RBCM nanoparticles with the PFC core show rather efficient loading of oxygen, as well as greatly prolonged blood circulation time owing to the coating of RBCM. With significantly improved extravascular diffusion within the tumor mass, owing to their much smaller nanoscale sizes compared to native RBCs with micrometer sizes, PFC@PLGA‐RBCM nanoparticles are able to effectively deliver oxygen into tumors after intravenous injection, leading to greatly relieved tumor hypoxia and thus remarkably enhanced treatment efficacy during RT. This work thus presents a unique type of nanoscale RBC mimic for efficient oxygen delivery into solid tumors, favorable for cancer treatment by RT, and potentially other types of therapy as well.     

pH‐Responsive Isoniazid‐Loaded Nanoparticles Markedly Improve Tuberculosis Treatment in Mice

Tuberculosis is a major global health problem for which improved therapeutics are needed to shorten the course of treatment and combat emergence of drug resistance. Mycobacterium tuberculosis, the etiologic agent of tuberculosis, is an intracellular pathogen of mononuclear phagocytes. As such, it is an ideal pathogen for nanotherapeutics because macrophages avidly ingest nanoparticles even without specific targeting molecules. Hence, a nanoparticle drug delivery system has the potential to target and deliver high concentrations of drug directly into M. tuberculosis‐infected cells—greatly enhancing efficacy while avoiding off‐target toxicities. Stimulus‐responsive mesoporous silica nanoparticles of two different sizes, 100 and 50 nm, are developed as carriers for the major anti‐tuberculosis drug isoniazid in a prodrug configuration. The drug is captured by the aldehyde‐functionalized nanoparticle via hydrazone bond formation and coated with poly(ethylene imine)–poly(ethylene glycol) (PEI–PEG). The drug is released from the nanoparticles in response to acidic pH at levels that naturally occur within acidified endolysosomes. It is demonstrated that isoniazid‐loaded PEI–PEG‐coated nanoparticles are avidly ingested by M. tuberculosis‐infected human macrophages and kill the intracellular bacteria in a dose‐dependent manner. It is further demonstrated in a mouse model of pulmonary tuberculosis that the nanoparticles are well tolerated and much more efficacious than an equivalent amount of free drug.     

NixMnyCozO Nanowire/CNT Composite Microspheres with 3D Interconnected Conductive Network Structure via Spray‐Drying Method: A High‐Capacity and Long‐Cycle‐Life Anode Material for Lithium‐Ion Batteries

The combination of high‐capacity and long‐term cycling stability is an important factor for practical application of anode materials for lithium‐ion batteries. Herein, Ni_xMn_yCo_zO nanowire (x + y + z = 1)/carbon nanotube (CNT) composite microspheres with a 3D interconnected conductive network structure (3DICN‐NCS) are prepared via a spray‐drying method. The 3D interconnected conductive network structure can facilitate the penetration of electrolyte into the microspheres and provide excellent connectivity for rapid Li⁺ ion/electron transfer in the microspheres, thus greatly reducing the concentration polarization in the electrode. Additionally, the empty spaces among the nanowires in the network accommodate microsphere volume expansion associated with Li⁺ intercalation during the cycling process, which improves the cycling stability of the electrode. The CNTs distribute uniformly in the microspheres, which act as conductive frameworks to greatly improve the electrical conductivity of the microspheres. As expected, the prepared 3DICN‐NCS demonstrates excellent electrochemical performance, showing a high capacity of 1277 mAh g^?1 at 1 A g^?1 after 2000 cycles and 790 mAh g^?1 at 5 A g^?1 after 1000 cycles. This work demonstrates a universal method to construct a 3D interconnected conductive network structure for anode materials     

Rapid Production of Cell‐Laden Microspheres Using a Flexible Microfluidic Encapsulation Platform

This study establishes a novel microfluidic platform for rapid encapsulation of cells at high densities in photocrosslinkable microspherical hydrogels including poly(ethylene glycol)‐diacrylate, poly(ethylene glycol)‐fibrinogen, and gelatin methacrylate. Cell‐laden hydrogel microspheres are advantageous for many applications from drug screening to regenerative medicine. Employing microfluidic systems is considered the most efficient method for scale‐up production of uniform microspheres. However, existing platforms have been constrained by traditional microfabrication techniques for device fabrication, restricting microsphere diameter to below 200 µm and making iterative design changes time‐consuming and costly. Using a new molding technique, the microfluidic device employs a modified T‐junction design with readily adjustable channel sizes, enabling production of highly uniform microspheres with cell densities (10–60 million cells mL^?1) and a wide range of diameters (300–1100 µm), which are critical for realizing downstream applications, through rapid photocrosslinking (≈1 s per microsphere). Multiple cell types are encapsulated at rates of up to 1 million cells per min, are evenly distributed throughout the microspheres, and maintain high viability and appropriate cellular activities in long‐term culture. This microfluidic encapsulation platform is a valuable and readily adoptable tool for numerous applications, including supporting injectable cell therapy, bioreactor‐based cell expansion and differentiation, and high throughput tissue sphere‐based drug testing assays.     

Magnetically Controlled Growth‐Factor‐Immobilized Multilayer Cell Sheets for Complex Tissue Regeneration

The scaffold‐free cell‐sheet technique plays a significant role in stem‐cell‐based regeneration. Furthermore, growth factors are known to direct stem cell differentiation and enhance tissue regeneration. However, the absence of an effective means to incorporate growth factors into the cell sheets hinders further optimization of the regeneration efficiency. Here, a novel design of magnetically controlled “growth‐factor‐immobilized cell sheets” is reported. A new Fe₃O₄ magnetic nanoparticle (MNP) coated with nanoscale graphene oxide (nGO@Fe₃O₄) is developed to label stem cells and deliver growth factors. First, the nGO@Fe₃O₄ MNPs can be easily swallowed by dental‐pulp stem cells (DPSCs) and have no influence on cell viability. Thus, the MNP‐labeled cells can be organized via magnetic force to form multilayered cell sheets in different patterns. Second, compared to traditional Fe₃O₄ nanoparticles, the graphene oxide coating provides plenty of carboxyl groups to bind and deliver growth factors. Therefore, with these nGO@Fe₃O₄ MNPs, bone‐morphogenetic‐protein‐2 (BMP2) is successfully incorporated into the DPSCs sheets to induce more bone formation. Furthermore, an integrated osteochondral complex is also constructed using a combination of DPSCs/TGFβ3 and DPSCs/BMP2. All these results demonstrate that the new cell‐sheet tissue‐engineering approach exhibits promising potential for future use in regenerative medicine.