A validated polyclonal antiserum-based immunoassay for assessment of HPV 16 L1 relative potency.

Vaccine potency is typically evaluated using an assay that acts as a surrogate for biological activity. Although in vivo vaccines better represent human immunological responses, in vitro assays are preferred due to lower variability, higher throughput, easier validation and ethical considerations. In in vitro determination of Human Papillomavirus (HPV), Virus-like particle (VLP) vaccine potency currently depends on monoclonal antibody assays. However, these reagents are hard to obtain and currently are not available commercially. In this work, a polyclonal antiserum-based immunoassay was developed to evaluate the relative potency of Alhydrogel formulated HPV 16 VLPs. The repeatability and specificity were evaluated, and found that the assay was sensitive to small amounts of non-VLP HPV 16 L1 proteins. Finally, the assay was tested in comparison to the mouse effective dose 50 (ED50) assay on a limited number of batches. The agreement between these results suggests this test as a suitable surrogate for the in vivo test.

The miR-429 suppresses proliferation and migration in glioblastoma cells and induces cell-cycle arrest and apoptosis via modulating several target genes of ERBB signaling pathway.

BACKGROUND: Glioblastoma multiforme (GBM) is an aggressive and lethal brain cancer, which is incurable with standard cancer treatments. miRNAs have great potential to be used for gene therapy due to their ability to modulate several target genes simultaneously. We found miR-429 is downregulated in GBM and has several predicted target genes from the ERBB signaling pathway using bioinformatics tools. ERBB is the most over-activated genetic pathway in GBM patients, which is responsible for augmented cell proliferation and migration in GBM. METHODS AND RESULTS: Here, miR-429 was overexpressed using lentiviral vectors in U-251 and U-87 GBM cells and it was observed that the expression level of several oncogenes of the ERBB pathway, EGFR, PIK3CA, PIK3CB, KRAS, and MYC significantly decreased, as shown by real-time PCR and western blotting. Using the luciferase assay, we showed that miR-429 directly targets MYC, BCL2, and EGFR. In comparison to scrambled control, miR-429 had a significant inhibitory effect on cell proliferation and migration as deduced from MTT and scratch wound assays and induced cell-cycle arrest and apoptosis in flow cytometry. CONCLUSIONS: Altogether, miR-429 seems to be an efficient suppressor of the ERBB genetic signaling pathway and a potential therapeutic for GBM.

In vivo bone regeneration using a bioactive nanocomposite scaffold and human mesenchymal stem cells.

Due to the osteoconductive role of bioceramics, use of these bioactive nanocomposite scaffolds that can maintain their structural integrity during bone tissue repair is one of the major goals of tissue engineering. Herein, a nanofibrous poly-L-lactic acid (PLLA) scaffold was fabricated by electrospinning and then gelatin and hydroxyapatite nanoparticles (nHA) were coated over the surface of the scaffold. Osteoconductivity of the fabricated nano-composite scaffolds was then studied while grafted on the rat calvarial defects. Our results indicated that the coating of PLLA scaffold with nHA and gelatin increased the adhesion and growth of the human bone marrow derived mesenchymal stem cells (BM-MSCs) and also significantly increased the level of mineralization over a week culture period. The results of radiographic and histological studies showed that the newly created bone tissue at the defect site was significantly higher in animals treated with nanocomposite scaffolds than the empty scaffolds and control groups. This increase in the defect reconstruction was significantly increased after culturing BM-MSCs on the scaffolds, especially nanocomposite scaffolds. It can be concluded that the combination of nanocomposite scaffolds and BM-MSCs could be a very good candidate for treatment of bone lesions and could be considered as a bony bioimplant.

Regeneration of Bone Defects in a Rabbit Femoral Osteonecrosis Model Using 3D-Printed Poly (Epsilon-Caprolactone)/Nanoparticulate Willemite Composite Scaffolds.

Steroid-associated osteonecrosis (SAON) is a chronic disease that leads to the destruction and collapse of bone near the joint that is subjected to weight bearing, ultimately resulting in a loss of hip and knee function. Zn2+ ions, as an essential trace element, have functional roles in improving the immunophysiological cellular environment, accelerating bone regeneration, and inhibiting biofilm formation. In this study, we reconstruct SAON lesions with a three-dimensional (3D)-a printed composite made of poly (epsilon-caprolactone) (PCL) and nanoparticulate Willemite (npW). Rabbit bone marrow stem cells were used to evaluate the cytocompatibility and osteogenic differentiation capability of the PCL/npW composite scaffolds. The 2-month bone regeneration was assessed by a Micro-computed tomography (micro-CT) scan and the expression of bone regeneration proteins by Western blot. Compared with the neat PCL group, PCL/npW scaffolds exhibited significantly increased cytocompatibility and osteogenic activity. This finding reveals a new concept for the design of a 3D-printed PCL/npW composite-based bone substitute for the early treatment of osteonecrosis defects.

Comparative evaluation of the effect of cold ceramic and MTA-Angelus on cell viability, attachment and differentiation of dental pulp stem cells and periodontal ligament fibroblasts: an in vitro study.

BACKGROUND: Biocompatibility and induction of mineralized tissue formation are the properties expected from a material used in vital pulp therapy and repair of perforations. Cold ceramic (SJM, Iran; CC) is a newly introduced calcium silicate-based cement for above mentioned therapeutic applications. This in-vitro study aimed to compare the effect of CC and White MTA-Angelus (MTA) on cell viability, attachment, odontogenic differentiation, and calcification potential of human dental pulp stem cells (DPSCs) and periodontal ligament fibroblasts (PDLFs). METHODS: Cell viability of DPSCs and PDLFs was assessed using MTT on days 1, 3, 7, and 14 (n = 9) in contact with freshly mixed and set states of CC and MTA. Field emission scanning electron micrographs (FESEM) were taken to evaluate cell-bioceramic interaction (n = 6). Gene expression levels of osteo/odontogenic markers (Dentin sialophosphoprotein, Dentin matrix protein 1, Collagen type I alpha 1, and Alkaline phosphatase (DSPP, DMP1, COL 1A1, and ALP, respectively) (n = 8) were assessed using qrt-PCR. ALP enzymatic activity was evaluated to assess the mineralization potential. A two-way ANOVA test was applied, and p < 0.05 was considered to be statistically significant. RESULTS: The effect of freshly mixed and set MTA and CC on the survival of DPSCs and PDLFs in all study groups was statistically similar and comparable to the positive control group (p > 0.05); the only exception was for the viability of PDLFs in contact with freshly mixed cements on day 1, showing a more significant cytotoxic effect compared to the control and the set state of materials (p < 0.05). PDLFs attached well on CC and MTA. The spread and pseudopodium formation of the cells increased on both samples from day 1 to day 14. Contact of MTA and CC with DPSCs similarly increased expression of all dentinogenesis markers studied on days 7 and 14 compared to the control group (p < 0.001), except for DSPP expression on day 7 (p = 0.46 and p = 0.99 for MTA and CC, respectively). CONCLUSIONS: Within the limitation of this in-vitro study, cold ceramic and MTA-Angelus showed high biocompatibility and induced increased expression of osteo/dentinogenic markers. Therefore, cold ceramic can be a suitable material for vital pulp therapy and the repair of root perforations.

MicroRNA-218 competes with differentiation media in the induction of osteogenic differentiation of mesenchymal stem cell by regulating ß-catenin inhibitors.

Osteoporosis, a systemic skeletal disorder specified by low bone mass, is associated with bone fragility and the raised risk of fractures. Activation of the Wnt/ß-catenin signaling pathway has been directly demonstrated as a prominent biological event in the prevention of osteoporosis. Recently, critical roles of microRNAs (miRNAs) were further revealed in Wnt/ß-catenin signaling activation and thereby contributing to the development and maintenance of the human skeleton. In this study, we investigated whether miR-218 can significantly promote the osteogenic differentiation of mesenchymal stem cells in conditional media by regulating ß-catenin signaling inhibitors. The pre-miRNA nucleotide sequence of miR-218 was cloned into the pEGP-miR vector. Next, human adipose tissue-derived mesenchymal stem cells (AD-MSCs) were isolated, characterized, and transfected using pEGP-miR-218.Subsequently, the osteogenic potential of AD-MSCs was investigated in different treated groups using alkaline phosphatase (ALP)activity, calcium mineral deposition, and the expression of osteogenesis-related genes. Finally, negative regulators of Wnt signaling targeted by miR-218 were bioinformatically predicted. Our results indicated a significant increase in the ALP activity, mineralization, and osteogenesis-related genes expression in the AD-MSCs transfected with pEGP-miR-218. Also, the bioinformatic surveys and gene expression results showed that adenomatosis polyposis coli (APC) and glycogen synthase kinase 3 (GSK3-ß) were downregulated in the transfected AD-MSCs in both differential and conditional media. This study provided evidence that miR-218 can promote osteogenic differentiation of AD-MSCs even in conditional media. Therefore, our findings suggest miR-218 as a putative novel therapeutic candidate in the context of osteoporosis and other bone metabolism-related diseases.

Optimized dose of synthetic analogues of Monophosphoryl lipid A as an effective alternative for formulating recombinant human papillomavirus vaccine.

Adjuvants are a crucial component of recombinant vaccines such as the human papillomavirus (HPV) vaccine. Monophosphoryl lipid A (MPL) extracted from Salmonella Minnesota lipopolysaccharide is used as an adjuvant for the HPV vaccine. Due to the limitations in accessibility and reproducibility of MPL, investigating synthetic analogues of MPL (synMPL) is urgently needed to overcome these limitations. In this study, female BALB/c mice were vaccinated by HPV vaccine formulated with synMPL and aluminum hydroxide gel in which the concentration of synMPL ranged from 0 to 100 µg/dose. Anti-HPV L1 VLP antibody was measured for each group through Indirect ELISA and compared with Cervarix and Gardasil vaccines as approved anti-HPV vaccines. SynMPL showed a concentration-dependent increase up to 50 µg/dose in the immunogenicity of the vaccine. Therefore, synMPL at concentration of 50 µg/dose was selected as optimum concentration. The GMT profiling of synMPL-formulated vaccine (named Papilloguard) and Cervarix was not statistically different (Mann-Whitney test). The Gardasil vaccine showed 10-fold lower GMT for anti-HPV 18 L1 VLP antibody but anti-HPV 16 L1 VLP antibody was similar to Cervarix and Papilloguard. The current findings suggest that the synMPL in combination with aluminum hydroxide could be used as a potential adjuvant candidate for human vaccine.

Pharmaceutical implants: classification, limitations and therapeutic applications.

Controlled/sustained delivery systems have been developed rapidly which show the ability to overcome the obstacles of traditional delivery systems. Daily development of biomedical and biomaterial sciences has brought more attention to the implantable delivery systems. As a result, these systems have found their position in the medical field since they were introduced. The advances in the polymeric science along with the other fields, make the production of a wide variety of implantable systems, possible. The influence of these systems in medical field could not be denied Here', the pharmaceutical applications which have been mostly focused on, are discussed. Since these systems have proven to be beneficial, researchers are trying to adjust their defects to the desired properties. Doing so, the path that implantable delivery systems have crossed so far should be studied, and that's the aim of this review. In the present report, the advantages of these systems in chemotherapeutic, contraceptive, neuropsychology, pain management, peptide delivery, ocular delivery, cardiovascular, orthopedic, and dental fields have been evaluated.

Dexamethasone loaded multi-layer poly-l-lactic acid/pluronic P123 composite electrospun nanofiber scaffolds for bone tissue engineering and drug delivery.

In tissue engineering, it is common to mix drugs that can control proliferation and differentiation of cells into polymeric solutions as part of composite to get bioactive scaffolds. However, direct incorporation of drugs might potentially result in undesired burst release. To overcome this problem, here we developed electrospun multilayer drug loaded poly-l-lactic acid/pluronic P123 (PLLA-P123) composite scaffolds. The drug was loaded into the middle layer. The surface, the mechanical and physiochemical properties of the scaffolds were evaluated. The drug release profiles were monitored. Finally, the osteogenic proliferation and differentiation potential were determined. The scaffolds fabricated here have appropriate surface properties, but with different mechanical strength and osteogenic proliferation and differentiation. Multi-layer scaffolds where the drug was in the middle layer and PLLA-plasma and PLLA-P123 with cover layer showed the best osteogenic proliferation and differentiation than the other groups of scaffolds. The drug release profiles of the scaffolds were completely different: single layer scaffolds showed burst release within the first day, while multilayer scaffolds showed controlled release. Therefore, the multilayer drug loaded scaffolds prepared have dual benefits can provide both better osteogenesis and controlled release of drugs and bioactive molecules at the implant site.

Osteoconduction of Unrestricted Somatic Stem Cells on an Electrospun Polylactic-Co-Glycolic Acid Scaffold Coated with Nanohydroxyapatite.

The limitation of traditional bone grafts could be overcome by applying engineered bone constructs, which are mainly produced by seeding suitable stem cells on appropriate scaffolds. So far, bone marrow-derived stromal cells have been the most applied cells in bone tissue engineering, but current data show that unrestricted somatic stem cells (USSCs) from human cord blood might actually be a better stem cell source due to the accessibility and noninvasive procedure of collection. In this study, we cultured USSCs on a plasma-treated electrospun polylactic-co-glycolic acid (PLGA) scaffold coated with nanohydroxyapatite (nHA). Adhesion and proliferation of USSCs on PLGA/nHA were assessed by scanning electron microscopy and MTT assay. Osteogenic differentiation of USSCs into osteoblast lineage cells was evaluated via alkaline phosphatase (ALP) activity and real-time polymerase chain reaction. Our observation showed that USSCs attached and proliferated on PLGA/nHA. Osteogenic differentiation was confirmed by increased ALP activity and OSTEONECTIN expression in USSCs on PLGA/nHA after the 1st week of the osteogenic period. Therefore, using USSCs on electrospun PLGA/nHA is a promising approach in bone tissue engineering.

Hardystonite-Coated Poly(l-lactide) Nanofibrous Scaffold and Efficient Osteogenic Differentiation of Adipose-Derived Mesenchymal Stem Cells.

In this study, a ceramic-coated nanofibrous scaffold has been fabricated to biomimic the microstructure of natural extracellular matrix and the stiffening inorganic compartment of bone. Poly-l-lactic acid (PLLA) nanofibers were electrospun and exposed to oxygen plasma to induce hydrophilicity and promote ceramic adsorption. Hardystonite (HS), which possesses superior osteoinduction potential over hydroxyapatite, was coated on plasma-treated PLLA nanofibers by drenching the nanofibers in HS suspension. Pure and composite PLLA-based scaffolds were characterized in terms of physical and biological properties. In vitro cultivation of adipose-derived mesenchymal stem cells (AMSCs) on the scaffolds displayed that the composite scaffold is able to further support cell attachment and proliferation. In case of osteogenic differentiation of AMSCs, HS coating significantly increased the synthesis and activity of alkaline phosphate over 21 days period. In addition, the composite scaffold showed improved mineralization. The expression level of osteonectin and osteocalcin genes was significantly enhanced by HS coating of nanofibers. The biological improvement of PLLA nanofibrous matrix in the presence of HS nanoparticles could either be attributed to the release and stimulatory effect of constituent ions of HS or to the modification of chemico-physical properties of the resultant ceramic by silicon and zinc present in HS.

Electrospun composite PLLA/Oyster shell scaffold enhances proliferation and osteogenic differentiation of stem cells.

In bone tissue engineering, bioceramics are of the most widely used materials for treatment of bone defects clinically. The composites of bioceramic/polymer fibrous scaffolds have been designed and developed to fulfill the mechanical and biological requirements of the damaged tissue. In the present study, oyster shell (OS) as a bioceramic in combination with the biodegradable and biocompatible poly (l-lactide) has been used to prepare a new tissue-engineered composite. The morphology, porosity, water contact angle and mechanical properties of scaffolds were investigated. Mesenchymal stem cells were also cultured on fabricated scaffolds to evaluate their potential to support cell proliferation and osteogenic differentiation. The SEM results indicated that the electrospun scaffolds were nanostructured and the OS were oriented along the fiber axis. The tensile strength and also the increased surface hydrophilicity of scaffolds after plasma treatment were suitable for tissue engineering applications. MTT assay demonstrated that the fabricated scaffolds were capable of supporting stem cell attachment and proliferation. Biomineralization measurements demonstrated the enhanced osteogenic differentiation of stem cells on composite PLLA/OS scaffolds. Taken together, these scaffolds were shown to hold promising potential for the treatment of bone defects in vivo.

Enhanced Skin Regeneration by Herbal Extract-Coated Poly-L-Lactic Acid Nanofibrous Scaffold.

The wound healing process is directly related to the type of treatment. Existing methods of treatment are not responsive enough for severe wounds. The aim of this study was the potential capacity investigation of poly-L-lactic acid (PLLA) nanofibrous scaffolds coated by aloe vera gel for wound dressing applications. In this study, electrospinning method was used for preparing PLLA nanofibers, and after characterization by SEM and MTT, its influence on the wound healing process was investigated with and without aloe vera gel as a wound dressing in full-thickness skin defect in mice. Band-Aids were used as a positive control and vaseline gauze as a negative control. SEM and MTT assays confirmed the nanometer size and biocompatibility of fabricated nanofibers. Macroscopic and histopathological characteristics were evaluated at the end of days 7, 12, and 17 and their results showed that the gel-coated scaffold accelerated the wound-healing process compared with other groups. At the end of the experiment, it was shown that during the whole time of study, gel-coated scaffold had the highest overall repair score. Therefore, gel-coated PLLA scaffold would be an ideal construct for wound healing and skin regenerative medicine application.

Insulin producing cells generation by overexpression of miR-375 in adipose-derived mesenchymal stem cells from diabetic patients.

Diabetes Mellitus (DM) is a systematic disease, which happens because of destruction of islets of Langerhans in the pancreas and systematic resistance to insulin. The lack of donor for pancreas transplantation and risk of transplant rejection is the main challenge in the treatment of this disease. Stem cells are proper and sufficient source for creating insulin-producing cells (IPC). In this study adipose tissue was provided from diabetic patients operated for liposuction and then adipose derived stem cells (ADSCs) were isolated, characterized and then treated by lentiviruses containing miR-375, after 7, 14 and 21 days of induction, islet-like clusters (ILC) specific genes including insulin and PDX1 were evaluated by Real Time RT-PCR. Finally, immunocytochemistry was also used for evaluation of these markers in the protein level. The results were shown that insulin and PDX1 genes and proteins expression significantly increased in transduced stem cells compared to the control group. According to the results it can be concluded that islet-like clusters can be achieved from ADSCs by overexpression of miR-375.

Extremely Low Frequency Electromagnetic Field in Mesenchymal Stem Cells Gene Regulation: Chondrogenic Markers Evaluation.

There is little evidence demonstrating the effects of electromagnetic fields (EMFs) generated within the biological entity and the effect of extrinsic fields on cellular programing. Taking the path of the more studied stimuli into attention, mechanical forces, it could be understood that nonchemical factors play a consequential role in transcriptional regulatory networks. Cartilaginous tissue consists of collagen protein that is considered as a piezoelectric substrate and is influenced by electric fields making chondrogenic specific genes an exciting candidate for bioelectromagnetic studies. As electromagnetic properties highly depend on the frequencies applied, this study delves into the ability of two EMFs with the frequency of 25 Hz and 50 Hz in inducing SOX9 and COL2 gene expressions in a three-dimensional (3D) mesenchymal stem cell (MSC)-alginate construct. Cell-alginate beads were divided into six groups and treated for a time period of 21 days. To determine the results, qualitative and quantitative data were both reviewed. On observation of real-time polymerase chain reaction (PCR) data, it was apparent that TGF-ß1 treatment had a greater COL2 and SOX9 gene expression impact on MSCs compared to pulsed electromagnetic field (PEMF) treatments alone. COL2 was shown to have a greater transcriptional tendency to PEMF, whereas under defined electromagnetic parameters applied in this study, no significant difference was detected in SOX9 gene expressions compared to the control group. PEMF co-treatments enhanced the deposition of extracellular matrix molecules, as the matrix-rich beads were positively stained by Alcian blue. This genre of study is the venue for the control and healing of connective tissue defects.

Enhancement of stem cell differentiation to osteogenic lineage on hydroxyapatite-coated hybrid PLGA/gelatin nanofiber scaffolds.

A combination of polymeric materials and bioceramics has recently received a great deal of attention for bone tissue engineering applications. In the present study, hybrid nanofibrous scaffolds were fabricated from PLGA and gelatin via electrospinning and then were coated with hydroxyapatite (HA). They were then characterized and used in stem cell culture studies for the evaluation of their biological behavior and osteogenic differentiation in vitro. This study showed that all PLGA, hybrid PLGA/gelatin and HA-PLGA/gelatin scaffolds were composed of ultrafine fibers with smooth morphology and interconnected pores. The MTT assay confirmed that the scaffolds can support the attachment and proliferation of stem cells. During osteogenic differentiation, bone-related gene expression, ALP activity and biomineralization on HA-PLGA/gelatin scaffolds were higher than those observed on other scaffolds and TCPS. PLGA/gelatin electrospun scaffolds also showed higher values of these markers than TCPS. Taking together, it was shown that nanofibrous structure enhanced osteogenic differentiation of adipose-tissue derived stem cells. Furthermore, surface-coated HA stimulated the effect of nanofibers on the commitment of stem cells toward osteolineage. In conclusion, HA-PLGA/gelatin electrospun scaffolds were demonstrated to have significant potential for bone tissue engineering applications.

Fat harvesting site is an important determinant of proliferation and pluripotency of adipose-derived stem cells.

To define the optimal fat harvest site and detect any potential differences in adipose-derived stem cells (ASCs) proliferation properties in camels, aspirates from the abdomen and hump sites were compared. Obtained results revealed that ASCs from both abdomen and hump exhibited spindle-shaped and fibroblast-like morphology with hump-derived ASCs being smaller in size and narrower in overall appearance than abdominal ASCs. Abdominal ASCs required a greater time for proliferation than the hump-derived cells. These results were further confirmed with a tetrazolium-based colorimetric assay (MTT) which showed a greater cell proliferation rate for hump ASCs than for the abdomen. Under inductive conditions, ASCs from both abdominal and hump fat deposits maintained their lineage differentiation potential into adipogenic, chondrogenic, and osteogenic lineages during subsequent passages without any qualitative difference. However, expression of alkaline phosphatase was higher in osteogenic differentiated cells from the hump compared with those of the abdomen. Moreover, the increase in calcium content in hump-derived stem cells was higher than that in abdominal-derived stem cells. In conclusion, our findings revealed that ASCs can be obtained from different anatomical locations, although ASCs from the hump fat region may be the ideal stem cell sources for use in cell-based therapies.

Kinetics of infected insect cell osmolysis and enhanced protein release using a modified disruption method.

We have studied and characterized a cell disruption method to produce a protein extract from recombinant Baculovirus infected insect cells based on osmotic lysis. Cell lysis kinetics were measured during a 24-h incubation in lysis buffer and resulting data sets were curve fitted to a hyperbola, visually similar to the Michaelis-Menten curve, to determine the maximum concentration of released protein and the time required to reach equilibrium. Effect of parameters such as pH, ionic strength and infection phase were evaluated, and based on fittings optimal protein release conditions were obtained for total cell protein as well as the recombinant protein, HPV 16 L1. It was demonstrated that pH and the phase of infection can vastly influence the amount of release while ionic strength only effects the time required to achieve equilibrium in protein release. Osmolysis can be a mild, yet effective method to release recombinant protein with high recovery levels and hence can be used in capacities where stringent criteria regarding contamination with surfactant or non-cytoplasmic contents are observed.

7SK small nuclear RNA inhibits cancer cell proliferation through apoptosis induction.

7SK small nuclear RNA (snRNA) is a 331-333-bp non-coding RNA, which recruits HEXIM 1/2 protein to inhibit positive elongation factor b (P-TEFb) activity. P-TEFb is an essential factor in alleviating promoter-proximal paused RNA polymerase II (Pol II) and initiating the productive elongation phase of gene transcription. Without this protein, Pol II will remain in its hypophosphorylated state, and no transcription occurs. In this study, we inhibited P-TEFb activity by over-expressing 7SK snRNA in human embryonic kidney (HEK) 293T cancer cell line. This inhibition led to a significant decrease in cell viability, which can be due to the transcription inhibition. Moreover, 7SK snRNA over-expression promoted apoptosis in cancerous cells. Our results suggest 7SK snRNA as a potential endogenous anti-cancer agent, and to the best of our knowledge, this is the first study that uses a long non-coding RNA's over-expression against cancer cell growth and proliferation.

Enhanced osteogenic differentiation of stem cells via microfluidics synthesized nanoparticles.

Advancement of bone tissue engineering as an alternative for bone regeneration has attracted significant interest due to its potential in reducing the costs and surgical trauma affiliated with the effective treatment of bone defects. We have improved the conventional approach of producing polymeric nanoparticles, as one of the most promising choices for drug delivery systems, using a microfluidics platform, thus further improving our control over osteogenic differentiation of mesenchymal stem cells. Molecular dynamics simulations were carried out for theoretical understanding of our experiments in order to get a more detailed molecular-scale insight into the drug-carrier interactions. In this work, with the sustained intracellular delivery of dexamethasone from microfluidics-synthesized nanoparticles, we explored the effects of particle design on controlling stem cell fates. We believe that the insights learned from this work will lead to the discovery of new strategies to tune differentiation for in situ differentiation or stem cell therapeutics. FROM THE CLINICAL EDITOR: The use of mesenchymal stem cells has been described by many researchers as a novel therapy for bone regeneration. One major hurdle in this approach is the control of osteogenic differentiation. In this article, the authors described elegantly their microfluidic system in which dexamethasone loaded nanoparticles were produced. This system would allow precise fabrication of nanoparticles and consequently higher efficiency in cellular differentiation.