Development of new nanofibrous nerve conduits by PCL-Chitosan-Hyaluronic acid containing Piracetam-Vitamin B12 for sciatic nerve: A rat model.

Peripheral nerve injury is a critical condition that can disrupt nerve functions. Despite the progress in engineering artificial nerve guidance conduits (NGCs), nerve regeneration remains challenging. Here, we developed new nanofibrous NGCs using polycaprolactone (PCL) and chitosan (CH) containing piracetam (PIR)/vitamin B12(VITB12) with an electrospinning method. The lumen of NGCs was coated by hyaluronic acid (HA) to promote regeneration in sciatic nerve injury. The NGCs were characterized via Scanning Electron Microscopy (SEM), Fourier transform infrared (FTIR), tensile, swelling, contact angle, degradation, and drug release tests. Neuronal precursor cell line (PCL12 cell) and rat mesenchymal stem cells derived from bone marrow (MSCs) were seeded on the nanofibrous conduits. After that, the biocompatibility of the NGCs was evaluated by the 2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, 4',6-diamidino-2-phenylindole (DAPI) staining, and SEM images. The SEM demonstrated that PCL/CH/PIR/VITB12 NGCs had nonaligned, interconnected, smooth fibers. The mechanical properties of these NGCs were similar to rat sciatic nerve. These conduits had an appropriate swelling and degradation rate. The In Vitro studies exhibited favorable biocompatibility of the PCL/CH/PIR/VITB12 NGCs towards PC12 cells and MSCs. The in vitro studies exhibited favorable biocompatibility of the PCL/CH/PIR/VIT B12 NGCs towards MSCs and PC12 cells. To analyze functional efficacy, NGCs were implanted into a 10 mm Wistar rat sciatic nerve gap and bridged the proximal and distal stump of the defect. After three months, the results of sciatic functional index (55.3 ± 1.8), hot plate latency test (5.6 ± 0.5 s), gastrocnemius muscle wet weight-loss (38.57 ± 1.6 %) and histopathological examination using hematoxylin-eosin (H&E) /toluidine blue/ Anti-Neurofilament (NF200) staining demonstrated that the produced conduit recovered motor and sensory functions and had comparable nerve regeneration compared to the autograft that can be as the gold standard to bridge the nerve gaps.

Good manufacturing practices production of human placental derived mesenchymal stem cells for therapeutic applications: focus on multiple sclerosis.

BACKGROUND: Among neurological diseases, multiple sclerosis (MS) affects mostly young adults and can cause long-term disability. While most medications with approval from regulatory agencies are very effective in treating MS disease, they are unable to repair the tissue damage found in the central nervous system (CNS). Consequently, Cell-based therapy particularly using mesenchymal stem/stromal cells (MSCs), holds promise for neuroprotection and tissue repair in MS treatment. Furthermore, placenta-derived MSCs (PLMSCs) have shown the potential to treat MS due to their abundance, noninvasive isolation from discarded tissues, no ethical problems, anti-inflammatory, and reparative properties. Accordingly, good manufacturing practices (GMPs) plays a crucial part in clinical SCs manufacturing. The purpose of our article is to discuss GMP-grade PLMSC protocols for treating MS as well as other clinical applications. METHODS AND RESULTS: Placental tissue obtained of a healthy donor during the caesarean delivery and PLMSCs isolated by GMP standards. Flow cytometry was used to assess the expression of the CD markers CD34, CD105, CD90, and CD73 in the MSCs and the mesodermal differentiation ability was evaluated. Furthermore, Genetic evaluation of PLMSCs was done by G-banded karyotyping and revealed no chromosomal instability. In spite of the anatomical origin of the starting material, PLMSCs using this method of culture were maternal in origin. CONCLUSIONS: We hope that our protocol for clinical manufacturing of PLMSCs according to GMP standards will assist researchers in isolating MSCs from placental tissue for clinical and pre-clinical applications.

Exploring the various effects of Cu doping in hydroxyapatite nanoparticle.

Adding foreign ions to hydroxyapatite (HAp) is a popular approach for improving its properties. This study focuses on the effects of calcium substitution with copper in HAp. Instead of calcium, copper ions were doped into the structure of hydroxyapatite nanoparticles at 1%, 3%, and 5% concentrations. XRD analysis showed that the amount of substituted copper was less than needed to generate a distinct phase, yet its lattice parameters and crystallinity slightly decreased. Further, the results of degradation tests revealed that copper doping in hydroxyapatite doubled calcium ion release in water. The incorporation of copper into the apatite structure also boosted the HAp zeta potential and FBS protein adsorption onto powders. According to antibacterial investigations, a concentration of 200 mg/ml of hydroxyapatite containing 5% copper was sufficient to effectively eradicate E. coli and S. aureus bacteria. Furthermore, copper improved hydroxyapatite biocompatibility. Alkaline phosphatase activity and alizarin red tests showed that copper in hydroxyapatite did not inhibit stem cell differentiation into osteoblasts. Also, the scratch test demonstrated that copper-containing hydroxyapatite extract increased HUVEC cell migration. Overall, our findings demonstrated the utility of incorporating copper into the structure of hydroxyapatite from several perspectives, including the induction of antibacterial characteristics, biocompatibility, and angiogenesis.

Tissue engineering and stem cell-based therapeutic strategies for premature ovarian insufficiency.

Premature ovarian insufficiency (POI), also known as premature ovarian failure (POF), is a complex endocrine disease that commonly affects women under the age of 40. It is characterized by the cessation of ovarian function before the age of 40, leading to infertility and hormonal imbalances. The currently available treatment options for POI are limited and often ineffective. Tissue engineering and stem cell-based therapeutic strategies have emerged as promising approaches to restore ovarian function and improve the quality of life for women affected by POI. This review aims to provide a comprehensive overview of the types of stem cells and biomaterials used in the treatment of POI, including their biological characteristics and mechanisms of action. It explores various sources of stem cells, including embryonic stem cells, induced pluripotent stem cells, and adult stem cells, and their potential applications in regenerating ovarian tissue. Additionally, this paper discusses the development of biomaterials and scaffolds that mimic the natural ovarian microenvironment and support the growth and maturation of ovarian cells and follicles. Furthermore, the review highlights the challenges and ethical considerations associated with tissue engineering and stem cell-based therapies for POI and proposes potential solutions to address these issues. Overall, this paper aims to provide a comprehensive overview of the current state of research in tissue engineering and stem cell-based therapeutic strategies for POI and offers insights into future directions for improving treatment outcomes in this debilitating condition.

Targeted expression of a designed fusion protein containing BMP2 into the lumen of exosomes.

BACKGROUND: Exosomes are 30-150 nm membrane vesicles, originating from the endocytic pathway. By acting as natural carriers of biomolecules, they can transfer various materials to recipient cells. Therefore, discovering novel strategies for cargo packaging into exosomes is crucial. METHODS: The fusion constructs, consisting of protein of interest (BMP2) along with the targeting motif, linkers, tracking proteins, and enzyme cleavage sites, were computationally designed. Following the homology modeling, the best structure was selected and subjected to molecular dynamics (MD) simulation and docking analyses. The fusion protein gene was expressed in the HEK-293LTV cell line. The high-efficiency transfected and transduced cells were screened and their exosomes were isolated. Finally, cell and exosome lysates were evaluated for expression of the fusion protein. RESULTS: A total of 12 constructs with lengths ranging from 483 to 496 were designed. The top three templates, 1REW, 2H5Q, and 2MOF were screened. MD simulation and docking analyses of the structures revealed their stability and functionality. In the protein expression analyses, three bands at sizes of approximately 60, 25, and 12.5 kDa were observed, consistent with the sizes of the complete fusion protein, dimeric, and monomeric BMP2 protein. The presence of a 12.5 kDa band at exosome lysate analysis might suggest that it was loaded and cleaved inside exosomes. CONCLUSION: In summary, these findings revealed that the proposed idea for cargo sorting within the exosome lumen through incorporating an appropriate cleavage site was effective, thus providing further insight into the potential of exosomes as nano-shuttles bearing therapeutic biomolecules.

Advances in Management of Spinal Cord Injury Using Stem Cell-derived Extracellular Vesicles: A Review Study.

Introduction: Spinal cord injury (SCI) is characterized by serious both motor and sensory disability of the limbs below the injured segment. It is the most traumatic disorder among central nervous system (CNS) conditions which not only leads to psychological and physical harm to patients but also results in a dramatic loss in the life quality. Many efforts have been developed to find a therapeutic approach for SCI; however, an effective treatment has not yet been found. The lack of effective treatment approach and rehabilitation of SCI underscores the need to identify novel approaches. Tissue engineering associated with stem cells has been recently introduced as an effective treatment approaches for traumatic SCI. Although, low survival rates, immune rejection, cell dedifferentiation, and tumorigenicity have been addressed for tissue engineering. Regenerative medicine is an interdisciplinary field developing and applying tissue engineering, stem cell (SC) therapy, and SC-derived extracellular vesicle therapy that aims to provide reliable and safe ways to replace injured tissues and organs. The application of mesenchymal stem cells-derived extracellular vesicles (MSC-EVs) has recently attracted attention to improve central nervous system dysfunction such as SCI, mainly by promoting neurogenesis and angiogenesis. Methods: In this review article the latest information of SCI improvement using stem cell-derived extracellular vesicles published data in the Web of Science, Scopus, Science Direct and Pub Med databases were collected. Results: The data collected show that MSC-EVs, including exosomes, alone or in combination with scaffolds can can regenerate the injured nerve in SCI. Conclusion: This study summarizes the efficacy of MSC-EVs, including exosomes, alone or in combination with scaffolds in the treatment of SCI and then discusses the therapeutic outcomes observed in SCI experimental models following treatment with MSC-EVs alone or loaded on scaffolds in particular collagen-based scaffolds. Highlights: The pathological process of SCI being very complex.A complete effective strategy has yet to be found for treatment of SCI in human.Exosomes derived-stem cells alone have great potential for the treatment of SCI.Various biocompatible scaffolds are good drug carriers for SCI treatment.Various biocompatible scaffolds are good carriers for exosomes. Plain Language Summary: Human with spinal cord injury (SCI) show serious motor and sensory disability of the limbs. Since there is no an effective treatment for SCI, researchers are trying to develop and find a new therapeutic approach for SCI. CNS tissue engineering with various stem cells sources as well as their derived extracellular vesicle has been extensively attracted for providing reliable and safe approach for SCI treatment. Extracellular vesicles are lipid bilayer membrane-enclosed organelles containing various biomolecules involved in a variety of complex intercellular communication systems. They are released from all cell types into their surrounding environment and are important vehicles for paracrine The application of stem cells-derived extracellular vesicles (MSC-EVs) has recently attracted attention to improve central nervous system dysfunction such as SCI, mainly by promoting neurogenesis and angiogenesis.

A Review on Treatment of Premature Ovarian Insufficiency: Characteristics, Limitations, and Challenges of Stem Cell versus ExosomeTherapy.

Premature ovarian insufficiency (POI) is a complex disorder that can result in varying degrees of infertility. Recently, mesenchymal stem cell (MSC) therapy and its derivatives, such as exosomes, have been introduced as novel strategies for the treatment of POI. This review discusses the features, limitations, and challenges of MSC and exosome therapy in the treatment of POI and provides readers with new insights for comparing and selecting chemical agents, optimizing doses, and other factors involved in study design and treatment strategies. MSC therapy has been shown to improve ovarian function in some animals with POI, but it can also have side effects such as high cost, time-consuming processes, limited lifespan and cell sources, loss of original characteristics during in vitro proliferation, dependence on specific culture environments, potential immune reactions, unknown therapeutic mechanisms, etc. However, exosome therapy is a newer therapy that has not been studied as extensively as MSC therapy, but that it has shown some promise in animal studies. The evidence for the effectiveness of MSC and exosome therapy is still limited, and more research is needed to determine whether these therapies are effective and safe for women with POI. This study presents a new perspective for researchers to advance their research in the fields of cell-based and cell-free therapies.

Tissue engineering studies in male infertility disorder.

Infertility is an important issue among couples worldwide which is caused by a variety of complex diseases. Male infertility is a problem in 7% of all men. In vitro spermatogenesis (IVS) is the experimental approach that has been developed for mimicking seminiferous tubules-like functional structures in vitro. Currently, various researchers are interested in finding and developing a microenvironmental condition or a bioartificial testis applied for fertility restoration via gamete production in vitro. The tissue engineering (TE) has developed new approaches to treat male fertility preservation through development of functional male germ cells. This makes TE a possible future strategy for restoration of male fertility. Although 3D culture systems supply the perception of the effect of cellular interactions in the process of spermatogenesis, formation of a native gradient of autocrine/paracrine factors in 3D culture systems have not been considered. These results collectively suggest that maintaining the microenvironment of testicular cells even in the form of a 3D-culture system is crucial in achieving spermatogenesis ex vivo. It is also possible to engineer the testicular structures using biomaterials to provide a supporting scaffold for somatic and stem cells. The insemination of these cells with GFs is possible for temporally and spatially adjusted release to mimic the microenvironment of the in situ seminiferous epithelium. This review focuses on recent studies and advances in the application of TE strategies to cell-tissue culture on synthetic or natural scaffolds supplemented with growth factors.

Cytotoxicity of WT1-reactive T cells against Wilms tumor: An implication for antigen-specific adoptive immunotherapy.

Introduction: T cells that recognize WT1 peptides have been shown to efficiently eliminate WT1-expressing tumor cells. This study was designed to investigate the feasibility of isolating WT1-reactive T cells from peripheral blood mononuclear cells (PBMCs) from healthy donors and patients with Wilms tumor, and to assess the cytotoxicity mediated by these cells against Wilms tumor cells (WiTu cells). Methods: WT1-reactive T cells were enriched and isolated by stimulating PBMCs with a WT1 peptide pool and interferon-γ capture-based immunomagnetic separation (IMS). Using the lactate dehydrogenase release assay, the in vitro cytotoxicity of the isolated cells and standard chemotherapy was evaluated on WiTu cells. Results: Higher proportions of WT1-reactive T cells were isolated from patients with Wilms tumor compared to those isolated from HDs. WT1-reactive T cells produced > 50% specific lysis when co-cultured with WT1+ WiTu cells at the highest effector-to-target (E:T) ratio in this study (i.e., 5:1), compared to <23% when co-cultured with WT1- WiTu cells at the same ratio. WT1-reactive T cells showed anti-tumoral activity in a dose-dependent manner and mediated significantly greater cytotoxicity than the non-WT1-reactive fraction of PBMCs on WT1+ WiTu cells. The cytotoxicity of standard chemotherapy was significantly lower than that of WT1-reactive T cells when co-cultured with WT1+ WiTu cells at E:T ratios of 2:1 and 5:1. Conclusion: WT1-reactive T cells can be effectively enriched from the PBMCs of patients with Wilms tumor. Ex vivo generated WT1-reactive T cells might be considered an adoptive immunotherapeutic option for WT1+ Wilms tumors.

Chemo-immune cell therapy by intratumoral injection of adoptive NK cells with capecitabine in gastric cancer xenograft model.

Introduction: Gastric cancer is one of the most commonly known malignancies and is the fifth cancer-related death globally. Whereas natural killer (NK) cells play a critical role in tumor elimination; therefore, adoptive NK cell therapy has become a promising approach in cancer cytotherapy. Hence, this study investigated the chemo-immune cell therapy in MKN-45 derived xenograft gastric cancer model. Methods: Three groups of animals have received the following treatments separately: activated NK cells, capecitabine, the combination of capecitabine and activated NK cells, and one was considered as the control group. Morphometric properties of tumor samples were evaluated at the end of the study. NK cells infiltration was evaluated by immunohistochemistry (IHC) of hCD56. Mitotic count and treatment response was assessed by hematoxylin and eosin (H&E) staining. The proliferation ratio to apoptosis was determined by IHC assessment of Ki67 and caspase 3. Results: The results indicated that the NK cell therapy could effectively decrease the mitotic count in pathology assessment, but the tumor was not completely eradicated. In combination with metronomic chemotherapy (MC) of capecitabine, NK cell therapy demonstrated a significant difference in tumor morphometric properties compared to the control group. The proliferation ratio to apoptosis was also in line with pathology data. Conclusion: Although NK cell therapy could effectively decrease the mitotic count in vivo, the obtained findings indicated lesser potency than MC despite ex vivo activation. In order to enhance NK cell therapy effectiveness, suppressive features of the tumor microenvironment and inhibitory immune checkpoints blockade should be considered.

Cell-free therapy based on extracellular vesicles: a promising therapeutic strategy for peripheral nerve injury.

Peripheral nerve injury (PNI) is one of the public health concerns that can result in a loss of sensory or motor function in the areas in which injured and non-injured nerves come together. Up until now, there has been no optimized therapy for complete nerve regeneration after PNI. Exosome-based therapies are an emerging and effective therapeutic strategy for promoting nerve regeneration and functional recovery. Exosomes, as natural extracellular vesicles, contain bioactive molecules for intracellular communications and nervous tissue function, which could overcome the challenges of cell-based therapies. Furthermore, the bioactivity and ability of exosomes to deliver various types of agents, such as proteins and microRNA, have made exosomes a potential approach for neurotherapeutics. However, the type of cell origin, dosage, and targeted delivery of exosomes still pose challenges for the clinical translation of exosome therapeutics. In this review, we have focused on Schwann cell and mesenchymal stem cell (MSC)-derived exosomes in nerve tissue regeneration. Also, we expressed the current understanding of MSC-derived exosomes related to nerve regeneration and provided insights for developing a cell-free MSC therapeutic strategy for nerve injury.

Enhanced spinal cord regeneration by gelatin/alginate hydrogel scaffolds containing human endometrial stem cells and curcumin-loaded PLGA nanoparticles in rat.

Spinal cord injury (SCI) is a serious problem with a high prevalence worldwide. The weak capability of the spinal cord for regeneration in association with upregulation of inflammatory factors is two key obstacles against a full SCI repair. Curcumin is a natural substance with anti-inflammatory and neuroprotective effects. Here, we have used a combined strategy using stem cells and hybrid hydrogel scaffolds loaded with curcumin for SCI repair. Curcumin-loaded PLGA nanoparticles were prepared, characterized, and encapsulated into gelatin/alginate hydrogel scaffolds, which were then seeded by human endometrial stem cells (hEnSCs). The resulting construct was studied using in vitro and in vivo experiments on rat models. DLS, SEM, Zeta potential, and FTIR data confirmed the successful addition of curcumin to PLGA nanoparticles. SEM analyses indicated the successful addition of curcumin-loaded nanoparticles into the gelatin/alginate scaffold, as well as the adherence of the seeded EnSCs. Based on the results, the prepared constructs not only allowed the controlled release of curcumin but also could support the survival and growth of hEnSCs. Based on the results of BBB and histological experiments, the highest BBB score was related to the combined strategy, consistent with histological outcomes, in which our hEnSC-seeded gelatin/alginate scaffold containing curcumin-loaded nanoparticles led to improved structures of the white and gray matters in the SCI site, being indicative of the superior nerve fiber regeneration, compared to other studied groups. These results indicate the efficiency of the proposed method for SCI repair and broaden the scope for subsequent studies on spinal cord regeneration.

Differentiation of human endometrial stem cells encapsulated in alginate hydrogel into oocyte-like cells.

Introduction: Human endometrial mesenchymal stem cells (hEnMSCs) are a rich source of mesenchymal stem cells (MSCs) with multi-lineage differentiation potential, making them an intriguing tool in regenerative medicine, particularly for the treatment of reproductive and infertility issues. The specific process of germline cell-derived stem cell differentiation remains unknown, the aim is to study novel ways to achieve an effective differentiation method that produces adequate and functioning human gamete cells. Methods: We adjusted the optimum retinoic acid (RA) concentration for enhancement of germ cell-derived hEnSCs generation in 2D cell culture after 7 days in this study. Subsequently, we developed a suitable oocyte-like cell induction media including RA and bone morphogenetic protein 4 (BMP4), and studied their effects on oocyte-like cell differentiation in 2D and 3D cell culture media utilizing cells encapsulated in alginate hydrogel. Results: Our results from microscopy analysis, real-time PCR, and immunofluorescence tests revealed that 10 µM RA concentration was the optimal dose for inducing germ-like cells after 7 days. We examined the alginate hydrogel structural characteristics and integrity by rheology analysis and SEM microscope. We also demonstrated encapsulated cell viability and adhesion in the manufactured hydrogel. We propose that in 3D cell cultures in alginate hydrogel, an induction medium containing 10 µM RA and 50 ng/mL BMP4 can enhance hEnSC differentiation into oocyte-like cells. Conclusion: The production of oocyte-like cells using 3D alginate hydrogel may be viable in vitro approach for replacing gonad tissues and cells.

Cancer immunotherapy via stem cell-derived NK cells.

NK cells are the first sentinels of the immune system that can recognize and eradicate transformed cells. Their activation without a need for additional signaling have attracted great attention on the use of NK cells as a promising option in cancer immunotherapy. However, the large-scale production of NK cells for successful NK cells therapy is a challenge that needs to be tackled. Engineering NK cells to avoid tumor escape and improve their antitumor potency are the other matters of focus that have widely been studied in the recent years. This paper reviews the most recent advances in the stem cell-derived NK cell technology and discusses the potential of the engineered NK cells for clinical applications in cancer immunotherapy.

NK cells are important cells in our body's defense system that can find and destroy tumor cells. These cells are made in bone marrow (in adults) or umbilical cord (in the embryonic period) from a population of cells called stem cells, and then released into the blood and lymph. Stem cells are the early ancestral cells that can differentiate into multiple cell types. Because the number and function of NK cells in a tumor context are reduced, thus we can use these stem cells to make lots of NK cells for treatment purposes. Scientists can also make these cells even better at killing tumors by changing them to have special sensors. In the end, NK cells are like superheroes that fight and kill tumor cells, and using stem cells to make them is a really promising way to help treat malignant diseases.

Tissue-Engineered Core-Shell Silk-Fibroin/Poly-l-Lactic Acid Nerve Guidance Conduit Containing Encapsulated Exosomes of Human Endometrial Stem Cells Promotes Peripheral Nerve Regeneration.

Nerve guide conduits (NGCs) have been shown to be less efficient than nerve autografts in peripheral nerve regeneration. To address this issue, we developed for the first time a novel tissue-engineered nerve guide conduit structure encapsulated with human endometrial stem cell (EnSC) derived exosomes, which promoted nerve regeneration in rat sciatic nerve defects. In this study, we initially indicated the long-term efficacy and safety impacts of newly designed double layered SF/PLLA nerve guide conduits. Then the regeneration effects of SF/PLLA nerve guide conduits containing exosomes derived from human EnSCs were evaluated in rat sciatic nerve defects. The human EnSC derived exosomes were isolated from the supernatant of human EnSC cultures and characterized. Subsequently, the human EnSC derived exosomes were encapsulated in constructed NGCs by fibrin gel. For in vivo studies, entire 10 mm peripheral nerve defects were generated in rat sciatic nerves and restored with NGC encapsulated with human EnSC derived exosomes (Exo-NGC group), nerve guide conduits, and autografts. The efficiency of the NGCs encapsulated with human EnSCs derived exosomes in assisting peripheral nerve regeneration was investigated and compared with other groups. The in vivo results demonstrated that encapsulated human EnSC derived exosomes in NGC (Exo-NGC) significantly benefitted nerve regeneration based on motor function, sensory reaction, and electrophysiological results. Furthermore, immunohistochemistry with histopathology results showed the formation of regenerated nerve fibers, along with blood vessels that newly were developed, as a result of the exosome functions in the Exo-NGC group. These outcomes illustrated that the newly designed core-shell SF/PLLA nerve guide conduit encapsulated with human EnSC derived exosomes enhanced the regeneration process of axons and improved the functional recovery of rat sciatic nerve defects. So, encapsulated human EnSC-derived exosomes in a core-shell SF/PLLA nerve guide conduit are a potential therapeutic cell-free treatment for peripheral nerve defects.

Assessment of the Efficacy of an LL-37-Encapsulated Keratin Hydrogel for the Treatment of Full-Thickness Wounds.

Wound healing remains a burdensome healthcare problem due to moisture loss and bacterial infection. Advanced hydrogel dressings can help to resolve these issues by assisting and accelerating regenerative processes such as cell migration and angiogenesis because of the similarities between their composition and structure with natural skin. In this study, we aimed to develop a keratin-based hydrogel dressing and investigate the impact of the delivery of LL-37 antimicrobial peptide using this hydrogel in treating full-thickness rat wounds. Therefore, oxidized (keratose) and reduced (kerateine) keratins were utilized to prepare 10% (w/v) hydrogels with different ratios of keratose and kerateine. The mechanical properties of these hydrogels with compressive modulus of 6-32 kPa and tan δ <1 render them suitable for wound healing applications. Also, sustained release of LL-37 from the keratin hydrogel was achieved, which can lead to superior wound healing. In vitro studies confirmed that LL-37 containing 25:75% of keratose/kerateine (L-KO25:KN75) would result in significant fibroblast proliferation (∼85% on day 7), adhesion (∼90 cells/HPF), and migration (73% scratch closure after 12 h and complete closure after 24 h). Also, L-KO25:KN75 is capable of eradicating both Gram-negative and Gram-positive bacteria after 18 h. According to in vivo assessment of L-KO25:KN75, wound closure at day 21 was >98% and microvessel density (>30 vessels/HPF at day 14) was significantly superior in comparison to other treatment groups. The mRNA expression of VEGF and IL-6 was also increased in the L-KO25:KN75-treated group and contributed to proper wound healing. Therefore, the LL-37-containing keratin hydrogel ameliorated wound closure, and also angiogenesis was enhanced as a result of LL-37 delivery. These results suggested that the L-KO25:KN75 hydrogel could be a sustainable substitute for skin tissue regeneration in medical applications.

Enhanced sciatic nerve regeneration with fibrin scaffold containing human endometrial stem cells and insulin encapsulated chitosan particles: An in vivo study.

BACKGROUND: Based on recent advances in tissue engineering and stem cell therapy in nervous system diseases treatments, this study aimed to investigate sciatic nerve regeneration using human endometrial stem cells (hEnSCs) encapsulated fibrin gel containing chitosan nanoparticle loaded by insulin (Ins-CPs). Stem cells and also Insulin (Ins), which is a strong signaling molecule in peripheral nerve regeneration, play an important role in neural tissue engineering. METHODS: The fibrin hydrogel scaffold containing insulin loaded chitosan particles was synthesized and characterized. Release profiles of insulin from hydrogel was determined through UV-visible spectroscopy. Also, human endometrial stem cells encapsulated in hydrogel and its cell biocompatibility were assigned. Furthermore, the sciatic nerve crush injury was carried out and prepared fibrin gel was injected at the crush injury site by an 18-gage needle. Eight and twelve weeks later, the recovery of motor and sensory function and histopathological evaluation were assessed. RESULTS: The in vitro experiments showed that the insulin can promote hEnSCs proliferation within a certain concentration range. Animals' treatment confirmed that developed fibrin gel containing Ins-CPs and hEnSCs significantly improves motor function and sensory recovery. Hematoxylin and Eosin (H&E) images provided from cross-sectional and, longitudinal-sections of the harvested regenerative nerve showed that regenerative nerve fibers had been formed and accompanied with new blood vessels in the fibrin/insulin/hEnSCs group. CONCLUSION: Our results demonstrated that the prepared hydrogel scaffolds containing insulin nanoparticles and hEnSCs could be considered as a potential biomaterial aimed at regeneration of sciatic nerves.

Sustained release of valproic acid loaded on chitosan nanoparticles within hybrid of alginate/chitosan hydrogel with/without stem cells in regeneration of spinal cord injury.

Hydrogels have been increasingly applied in tissue regeneration and drug delivery systems (DDS). In this study, the capacity of valproic acid (Val) encapsulated within hybrid of alginate (Alg)-chitosan (Cs) (Alg-Cs) hydrogel containing Cs nanoparticle (Npch) with/without human endometrial stem cells (hEnSC) was initially examined for regeneration of spinal cord injury (SCI). To evaluate the stability of the synthesized hydrogels zeta potential necessary measurements were made. Physicochemically, the developed hydrogels were evaluated using Fourier-transform infrared (FTIR) spectroscopy. The physical properties including degradation rate, swelling ability, and tunability of the synthesized hydrogels were studied. To evaluate the nerve regeneration ability of the synthesized hydrogels, 35 Sprague-Dawley rats were undergone SCI. The spinal cords were exposed using laminectomy in T9-T10 area and the hemi-section SCI model was made. The rats were then randomly divided into 5 groups (n = 7) including, Alg-Cs/Npch, Alg-Cs/Npch/hEnSCs, Alg-Cs/Npch/Val, and Alg-Cs/Npch/hEnScs/Val, and the control groups without any intervention. The FTIR spectra showed band frequencies and assignments of Val, Alg-Cs, and alginate. Nanoparticles were formulated with a mean diameter of 187 and 210 nm, for Val/Alg-Cs and Alg-Cs, respectively. The loading of Val into Alg-Cs led to its reduced size by about 40 nm. The Cs-Npch/Val hydrogels degraded faster than the Alg-Cs-/Npch/Val hydrogel specifically in extended time of incubation. A higher swelling capacity of Alg-Cs/Npch hydrogel, compared to Cs/Npch/Val and Alg-Cs/Npch/Val hydrogels, was found. The Cs-Npch/Val hydrogels degraded faster than Alg-Cs-/Npch/Val hydrogel. The Alg-Cs/Npch/hEnSCs/Val could regenerate the damaged nerve fibers and histologically prevent the SCI-induced vacuolization spaces. The prepared Alg-Cs/Npch/Val could be a suitable polymeric carrier for taurine drugs as bioactive substrate in nerve tissue engineering (NTE) and DDS.

Reliable Kinetics for Drug Delivery with a Microfluidic Device Integrated with the Dialysis Bag.

The clinical success of a drug delivery system turns back to performing experiments with more reliable data. The dialysis bag has been one of the most employed technologies to monitor drug release from nanocarriers, membranes, and scaffolds. Unfortunately, this technology has several challenges regarding the accuracy of the obtained results. In this study, the development of a new system by integrating a microfluidic device and dialysis bag named "MF-dialysis" was carried out to evaluate the accuracy of the reported data. The release study was performed focusing on two drug delivery systems: (i) nanocarrier: Artemisia Absinthium extract-loaded soy protein isolate nanoparticle and (ii) sodium alginate film loaded with the nanocarrier. The obtained nanocarrier was analyzed by SEM, DLS, and zeta potential. The final experimental data were modeled using SigmaPlot software. Based on the results, two distinct but fitted models for the dialysis bag (power model, R2 = 0.99) and MF-dialysis (exponential model, R2 = 0.95) were obtained. MF-dialysis approved that after a while, NPs and films showed more drug release compared to the dialysis bag. To sum up, the MF-dialysis system can be a good candidate for a quick and more reliable study of drug delivery systems.