Aptamer-functionalized mesenchymal stem cells-derived exosomes for targeted delivery of SN38 to colon cancer cells.

Objectives: Known as natural nanovesicles, exosomes have attracted increased attention as biocompatible carriers throughout recent years, which can provide appropriate sources for incorporating and transferring drugs to desired cells in order to improve their effectiveness and safety. Materials and Methods: This study implicates the isolation of mesenchymal stem cells from adipocyte tissue (ADSCs) to acquire a proper amount of exosomes for drug delivery. As the exosomes were separated by ultracentrifugation, SN38 was entrapped into ADSCs-derived exosomes through the combination method of incubation, freeze-thaw, and surfactant treatment (SN38/Exo). Then, SN38/Exo was conjugated with anti-MUC1 aptamer (SN38/Exo-Apt), and its targeting ability and cytotoxicity towards cancer cells were investigated. Results: Encapsulation efficiency of SN38 into exosomes (58%) was significantly increased using our novel combination method. Furthermore, the in vitro results were indicative of the great cellular uptake of SN38/Exo-Apt and its significant cytotoxicity on Mucin 1 overexpressing cells (C26 cancer cells) without noticeable cytotoxicity on normal cells (CHO cells). Conclusion: The results propose that our approach developed an efficient method for loading SN38 as a hydrophobic drug into exosomes and decorating them with MUC1 aptamer against Mucin 1 overexpressing cells. So, SN38/Exo-Apt could be considered a great platform in the future for the therapy of colorectal cancer.

Biomaterials for Regenerative Medicine in Italy: Brief State of the Art of the Principal Research Centers.

Regenerative medicine is the branch of medicine that effectively uses stem cell therapy and tissue engineering strategies to guide the healing or replacement of damaged tissues or organs. A crucial element is undoubtedly the biomaterial that guides biological events to restore tissue continuity. The polymers, natural or synthetic, find wide application thanks to their great adaptability. In fact, they can be used as principal components, coatings or vehicles to functionalize several biomaterials. There are many leading centers for the research and development of biomaterials in Italy. The aim of this review is to provide an overview of the current state of the art on polymer research for regenerative medicine purposes. The last five years of scientific production of the main Italian research centers has been screened to analyze the current advancement in tissue engineering in order to highlight inputs for the development of novel biomaterials and strategies.

Stem cell membrane, stem cell-derived exosomes and hybrid stem cell camouflaged nanoparticles: A promising biomimetic nanoplatforms for cancer theranostics.

Nanomedicine research has advanced dramatically in recent decades. Nonetheless, traditional nanomedicine faces significant obstacles such as the low concentration of the drug at target sites and accelerated removal of the drug from blood circulation. Various techniques of nanotechnology, including cell membrane coating, have been developed to address these challenges and to improve targeted distribution and redcue cell membrane-mediated immunogenicity. Recently, stem cell (SC) membranes, owing to their immunosuppressive and regenerative properties, have grabbed attention as attractive therapeutic carriers for targeting specific tissues or organs. Bioengineering strategies that combine synthetic nanoparticles (NPs) with SC membranes, because of their homing potential and tumor tropism, have recently received a lot of publicity. Several laboratory experiments and clinical trials have indicated that the benefits of SC-based technologies are mostly related to the effects of SC-derived exosomes (SC-Exos). Exosomes are known as nano-sized extracellular vehicles (EVs) that deliver particular bioactive molecules for cell-to-cell communication. In this regard, SC-derived exosome membranes have recently been employed to improve the therapeutic capability of engineered drug delivery vehicles. Most recently, for further enhancing NPs' functionality, a new coating approach has been offered that combines membranes from two separate cells. These hybrid membrane delivery vehicles have paved the way for the development of biocompatible, high-efficiency, biomimetic NPs with varying hybrid capabilities that can overcome the drawbacks of present NP-based treatment techniques. This review explores stem cell membranes, SC-Exos, and hybrid SC-camouflaged NPs preparation methods and their importance in cancer therapy.

Exosomes Derived from Dental Pulp Stem Cells Show Different Angiogenic and Osteogenic Properties in Relation to the Age of the Donor.

Craniofacial tissue reconstruction still represents a challenge in regenerative medicine. Mesenchymal stem cell (MSC)-based tissue engineering strategies have been introduced to enhance bone tissue repair. However, the risk of related complications is limiting their usage. To overcome these drawbacks, exosomes (EXOs) derived from MSCs have been recently proposed as a cell-free alternative to MSCs to direct tissue regeneration. It was hypothesized that there is a correlation between the biological properties of exosomes derived from the dental pulp and the age of the donor. The aim of the study was to investigate the effect of EXOs derived from dental pulp stem cells of permanent teeth (old donor group) or exfoliated deciduous teeth (young donor group) on MSCs cultured in vitro. Proliferation potential was evaluated by doubling time, and commitment ability by gene expression and biochemical quantification for tissue-specific factors. Results showed a well-defined proliferative influence for the younger donor aged group. Similarly, a higher commitment ability was detected in the young group. In conclusion, EXOs could be employed to promote bone regeneration, likely playing an important role in neo-angiogenesis in early healing phases.

Active Materials for 3D Printing in Small Animals: Current Modalities and Future Directions for Orthopedic Applications.

The successful clinical application of bone tissue engineering requires customized implants based on the receiver's bone anatomy and defect characteristics. Three-dimensional (3D) printing in small animal orthopedics has recently emerged as a valuable approach in fabricating individualized implants for receiver-specific needs. In veterinary medicine, because of the wide range of dimensions and anatomical variances, receiver-specific diagnosis and therapy are even more critical. The ability to generate 3D anatomical models and customize orthopedic instruments, implants, and scaffolds are advantages of 3D printing in small animal orthopedics. Furthermore, this technology provides veterinary medicine with a powerful tool that improves performance, precision, and cost-effectiveness. Nonetheless, the individualized 3D-printed implants have benefited several complex orthopedic procedures in small animals, including joint replacement surgeries, critical size bone defects, tibial tuberosity advancement, patellar groove replacement, limb-sparing surgeries, and other complex orthopedic procedures. The main purpose of this review is to discuss the application of 3D printing in small animal orthopedics based on already published papers as well as the techniques and materials used to fabricate 3D-printed objects. Finally, the advantages, current limitations, and future directions of 3D printing in small animal orthopedics have been addressed.

Exosomes as Neurological Nanosized Machines.

In the past few decades, nanomedicine research has advanced dramatically. In spite of this, traditional nanomedicine faces major obstacles, such as blood-brain barriers, low concentrations at target sites, and rapid removal from the body. Exosomes as natural extracellular vesicles contain special bioactive molecules for cell-to-cell communications and nervous tissue function, which could overcome the challenges of nanoparticles. Most recently, microRNAs, long noncoding RNA, and circulating RNA of exosomes have been appealing because of their critical effect on the molecular pathway of target cells. In this review, we have summarized the important role of exosomes of noncoding RNAs in the occurrence of brain diseases.

Suicide due to fear of COVID-19, in the last month of pregnancy, leads to neonatal seizure: A case report.

INTRODUCTION: and importance: Limited data are available about various effects of COVID-19 on pregnancy. On the other hand, the COVID-19 pandemic could exacerbate anxiety or schizophrenia symptoms. CASE PRESENTATION: The patient is a 5-day-old newborn, whom his mother suffers from schizophrenia, depression and anxiety disorders. The young pregnant mother gets delusions of being infected with Covid-19, thus attempts suicide with Sertraline, Clonazepam, Quetiapine and Rispeirdone, although she was in the last week of pregnancy. The newborn baby referred to our neonatal ward with seizure and apnea. Phenytoin and caffeine were administered leading to some degree of symptom relief, but due to the dermatologic reactions of phenytoin, they were replaced with levetiracetam. CLINICAL DISCUSSION: The Covid-19 may increase levels of anxiety and depression or exacerbation of schizophrenia symptoms, especially in pregnant women suffering from mental disorders. In addition, there are evidence supporting the occurrence of neonatal malformations as a result of exposure to antipsychotic drugs during the first trimester of pregnancy. CONCLUSION: Investigating the role of antidepressant and antipsychotic drugs in the perinatal period, especially near delivery has received less attention so far; thus further studies are required to determine the safety of these drugs.

Multifunctional and Self-Healable Intelligent Hydrogels for Cancer Drug Delivery and Promoting Tissue Regeneration In Vivo.

Regenerative medicine seeks to assess how materials fundamentally affect cellular functions to improve retaining, restoring, and revitalizing damaged tissues and cancer therapy. As potential candidates in regenerative medicine, hydrogels have attracted much attention due to mimicking of native cell-extracellular matrix (ECM) in cell biology, tissue engineering, and drug screening over the past two decades. In addition, hydrogels with a high capacity for drug loading and sustained release profile are applicable in drug delivery systems. Recently, self-healing supramolecular hydrogels, as a novel class of biomaterials, are being used in preclinical trials with benefits such as biocompatibility, native tissue mimicry, and injectability via a reversible crosslink. Meanwhile, the localized therapeutics agent delivery is beneficial due to the ability to deliver more doses of therapeutic agents to the targeted site and the ability to overcome post-surgical complications, inflammation, and infections. These highly potential materials can help address the limitations of current drug delivery systems and the high clinical demand for customized drug release systems. To this aim, the current review presents the state-of-the-art progress of multifunctional and self-healable hydrogels for a broad range of applications in cancer therapy, tissue engineering, and regenerative medicine.

Advanced Hydrogels as Exosome Delivery Systems for Osteogenic Differentiation of MSCs: Application in Bone Regeneration.

Hydrogels are known as water-swollen networks formed from naturally derived or synthetic polymers. They have a high potential for medical applications and play a crucial role in tissue repair and remodeling. MSC-derived exosomes are considered to be new entities for cell-free treatment in different human diseases. Recent progress in cell-free bone tissue engineering via combining exosomes obtained from human mesenchymal stem cells (MSCs) with hydrogel scaffolds has resulted in improvement of the methodologies in bone tissue engineering. Our research has been actively focused on application of biotechnological methods for improving osteogenesis and bone healing. The following text presents a concise review of the methodologies of fabrication and preparation of hydrogels that includes the exosome loading properties of hydrogels for bone regenerative applications.

Recent advances of dendrimer in targeted delivery of drugs and genes to stem cells as cellular vehicles.

Stem cells can be used to repair dysfunctional and injured (or cancerous) tissues by delivering therapeutics. However, in comparison with other cells, it is harder to transfect drugs or genes into stem cells. Dendrimers have been considered as efficient vectors to deliver both genes and drugs to stem cells due to their unique properties including adjustable molecular weight and size, low toxicity, high loading capacity, and having multiple peripheral chemical agents which can be functionalized to improve deliverance efficiency. In this review, we discuss dendrimer-mediated drug and gene delivery to stem cells as cellular vehicles and the role of this strategy in treating a variety of disorders via regenerative medicine approaches.

Nanocarriers, Progenitor Cells, Combinational Approaches, and New Insights on the Retinal Therapy.

Progenitor cells derived from the retinal pigment epithelium (RPECs) have shown promise as therapeutic approaches to degenerative retinal disorders including diabetic retinopathy, age-related macular degeneration and Stargardt disease. However, the degeneration of Bruch's membrane (BM), the natural substrate for the RPE, has been identified as one of the major limitations for utilizing RPECs. This degeneration leads to decreased support, survival and integration of the transplanted RPECs. It has been proposed that the generation of organized structures of nanofibers, in an attempt to mimic the natural retinal extracellular matrix (ECM) and its unique characteristics, could be utilized to overcome these limitations. Furthermore, nanoparticles could be incorporated to provide a platform for improved drug delivery and sustained release of molecules over several months to years. In addition, the incorporation of tissue-specific genes and stem cells into the nanostructures increased the stability and enhanced transfection efficiency of gene/drug to the posterior segment of the eye. This review discusses available drug delivery systems and combination therapies together with challenges associated with each approach. As the last step, we discuss the application of nanofibrous scaffolds for the implantation of RPE progenitor cells with the aim to enhance cell adhesion and support a functionally polarized RPE monolayer.

Evaluation of wound healing efficiency of vancomycin-loaded electrospun chitosan/poly ethylene oxide nanofibers in full thickness wound model of rat.

Electrospun hybrid nanofibers have been extensively regarded as drug carriers. This study tries to introduce a nano fibrous wound dressing as a new strategy for a topical drug-delivery system. The vancomycin (VCM)-loaded hybrid chitosan/poly ethylene oxide (CH/PEO) nanofibers were fabricated by the blend-electrospinning process. Morphological, mechanical, chemical, and biological properties of nanofibers were examined by SEM, FTIR, release profile study, tensile assay, Alamar Blue cytotoxicity evaluation, and antibacterial activity assay. In vivo wound healing activity of hybrid CH/PEO/VCM nanofibers was evaluated in full-thickness skin wounds of rats. The hybrid CH/PEO/VCM nanofibers were successfully fabricated in a nanometer. The CH/PEO/VCM 2.5% had higher Young's Modulus, better tensile strength, smaller fiber diameter with sustained-release profiles compared to CH/PEO/VCM 5%. All nanofibers did not show any significant cytotoxicity (P < 0.05) on the normal fibroblast cells. Also, VCM-load hybrid CH/PEO nanofibers successfully inhibited bacterial growth. The wound area in the rats treated with CH/PEO/VCM 2.5% was less than CH/PEO/VCM 5% treated group. According to histological evaluation, the CH/PEO/VCM 2.5% group showed the fastest wound healing than other treatment groups. Results of this study proposed that CH/PEO/VCM nanofibers could promote the wound healing process by reducing the side effects of VCM as a topical antimicrobial agent.

Comparison Study of Stem Cell-Derived Extracellular Vesicles for Enhanced Osteogenic Differentiation.

Stem cell-derived extracellular vesicles (EVs) have shown great promise in the field of regenerative medicine and tissue engineering. Recently, human bone marrow-derived mesenchymal stem cell (BMSC)-derived EVs have been considered for bone tissue engineering applications. In this study, we evaluated the osteogenic capability of placental stem cell (PSC)-derived EVs and compared them to the well-characterized BMSC-derived EVs. EVs were extracted from three designated time points (0, 7, and 21 days) after osteogenic differentiation. The results showed that the PSC-derived EVs had much higher protein and lipid concentrations than EVs derived from BMSCs. The extracted EVs were characterized by observing their morphology and size distribution before utilizing next-generation sequencing to determine their microRNA (miRNA) profiles. A total of 306 miRNAs within the EVs were identified, of which 64 were significantly expressed in PSC-derived EVs that related to osteogenic differentiation. In vitro osteogenic differentiation study indicated the late-stage (21-day extracted)-derived EVs higher osteogenic enhancing capability when compared with the early stage-derived EVs. We demonstrated that EVs derived from PSCs could be a new source of EVs for bone tissue engineering applications.

Teicoplanin-loaded chitosan-PEO nanofibers for local antibiotic delivery and wound healing.

Antibiotic-loaded nano-delivery systems offer an advanced approach to overcome several limitations associated with antibiotic therapy. Antibiotic-loaded nanofibers can be applied topically for skin and wound healing, post operation implants for the prevention of abdominal adhesion, and prophylaxis and treatment of infections in orthopedic surgery. Here, the authors report the development of local antibiotic delivery system using chitosan- polyethylene oxide (PEO) nanofibers for delivery of teicoplanin. Successful electrospinning of chitosan-PEO solution containing 2 and 4 w/v% teicoplanin resulted in uniform and bead-less nanofibers. Nanofibers were able to release teicoplanin up to 12 days. Antibacterial test in agar diffusion and time-kill study on Staphylococcus aureus also demonstrate that loading teicoplanin in chitosan-PEO nanofibers not only kept the antibacterial activity of antibiotic but also, enhanced it up to 1.5 to 2 fold. Teicoplanin loaded nanofibers did not show any cytotoxicity to human fibroblast. Moreover, in vivo study on rat full thickness wound model confirmed safety and efficacy of applying teicoplanin loaded nanofibers and significant improve in wound closure was observed especially with nanofibers containing 4% teicoplanin. The sustained release profile, enhanced drug activity, cytocompatibility, and significant wound healing activity affirm the potential applications of teicoplanin-loaded nanofibers in wound healing and local antibiotic delivery.

Cholesterol-conjugated PEGylated PAMAM as an efficient nanocarrier for plasmid encoding interleukin-12 immunogene delivery toward colon cancer cells.

IL-12 is a pleiotropic cytokine, which shows an ideal applicant for tumor immunotherapy, because of its features of creating an interconnection between innate (NK cells) and adaptive (cytotoxic T lymphocyte) immunity. IL-12 gene therapy is a useful technique to deliver an immune-modulatory gene directly into tumor site thereby limiting the adverse effects of systemic administration of IL-12 proteins. One of the most largely investigated non-viral gene carriers is polyamidoamine (PAMAM). In the current research, 5 and 3% of PAMAM primary amines were substituted to transmit the plasmid encoding IL-12 gene to cells by cholesteryl chloroformate and alkyl-PEG, respectively. The features of modified PAMAMs containing size and surface charge density, cytotoxicity, and transfection efficiency were investigated in colon cancer cells. in vitro experiment showed that this modified carrier with average size of about 160 nm and zeta potential of 30 mV was able to increase the level of IL-12 production up to two folds as compared to that of the unmodified PAMAM. Improvement of the polymer hydrophobic balance along with of the modulation of the surface positive charge could provide an efficient and safe non-viral IL-12 gene for colon cancer immunogene therapy.

Co-delivery of doxorubicin and TRAIL plasmid by modified PAMAM dendrimer in colon cancer cells, in vitro and in vivo evaluation.

One strategy for cancer treatment is combination therapy using nanoparticles (NPs), which has resulted in enhanced anti-cancer effects and reduced cytotoxicity of therapeutic agents. Polyamidoamine dendrimer (PAMAM) has attracted considerable attention because of its potential applications ranging from drug delivery to molecular encapsulation and gene therapy. In this study, PAMAM G5 modified with cholesteryl chloroformate and alkyl-PEG was applied for co-delivery of doxorubicin (DOX) and plasmid encoding TRAIL into colon cancer cells, in vitro and in vivo. The results showed DOX was efficiently encapsulated in modified carrier (M-PAMAM) with loading level about 90%, and the resulting DOX-loaded M-PAMAM complexed with TRAIL plasmid showed much stronger antitumor effect than M-PAMAM containing DOX or TRAIL plasmid. On the other hand, the obtained results demonstrated that the treatment of mice bearing C26 colon carcinoma with this developed co-delivery system significantly decreased tumor growth rate. Thus, this modified PAMAM G5 can be considered as a potential carrier for co-delivery of drug and gene in cancer therapy.

Bromelain-loaded chitosan nanofibers prepared by electrospinning method for burn wound healing in animal models.

Bromelain is a mixture of proteolytic enzymes present in all tissues of pineapple (Ananas comosus). It is known as an efficient debriding agent in burn treatment. In this study, the efficiency of bromelain-loaded chitosan nanofibers for burn wounds repair was investigated in animal model. Chitosan nanofibers containing bromelain (2% and 4% w/v) were prepared by electrospinning method. The physicochemical characteristics of the synthetized nanofibers were evaluated. The release profile and activity of bromelain loaded in nanofibers were also assayed. Cytotoxicity test was carried out using Alamar blue. The burn healing effect of chitosan-2% w/v bromelain nanofiber was studied in the induced burn wounds in rats for 21 days. The efficacy of treatment was assessed by reduction of burn wound area and histological characteristics at different times. Chitosan-2% w/v bromelain showed the better physicochemical properties and release profile as well as low cytotoxicity than chitosan-4% w/v bromelain. The results also indicated that chitosan-2% w/v bromelain nanofiber was more efficient to heal burn skin compared to chitosan nanofiber alone in the animal model tested. The present study concludes that chitosan-2% w/v bromelain nanofiber possesses great wound healing activity and could be considered as an effective natural topical burn wound healing treatment.

Modified PAMAM vehicles for effective TRAIL gene delivery to colon adenocarcinoma: in vitro and in vivo evaluation.

TRAIL (tumour necrosis factor-related apoptosis-inducing ligand) gene therapy is considered as one of the promising approaches for cancer treatment. Polyamidoamine (PAMAM) is one of the most extensively applied polymeric vector in gene delivery. In the current study, PAMAM (G4 and G5) dendrimers were modified with alkyl-carboxylate chain, PEG and cholesteryl chloroformate in order to enhance transfection efficiency through overcoming extracellular and intracellular barriers while reducing PAMAM cytotoxicity. Gene delivery efficiency of synthetized vectors was evaluated by both GFP (green fluorescent protein) reporter gene and TRAIL plasmid in colon cancer cells, in vitro and in vivo. The obtained results demonstrated that PAMAM G4-alkyl-PEG (3%)-Chol (5%)-TRAIL complexes at C/P ratio 4 could significantly increase cell death (29.45%) in comparison with unmodified PAMAM vector (15.5%). Moreover, in vivo study in C26 tumor-bearing BALB/c mice suggested that the prepared non-toxic safe vector could inhibit the tumor growth. This study represented the potent vehicle based on cholesterol-grafted PAMAM dendrimers with alkyl-PEG modification for efficient gene delivery in vitro and in vivo.

Comparison of the effect of crocin and crocetin, two major compounds extracted from saffron, on osteogenic differentiation of mesenchymal stem cells.

BACKGROUND: Mesenchymal stem cells (MSCs) can be considered as an effective tool for bone regeneration. It is variable to find new agents with low cytotoxicity and high efficiency for induction of MSCs into osteoblasts. In the present study, the ability of crocin and crocetin, extracted from saffron, to induce cell differentiation of rat bone marrow-derived mesenchymal stem cells (rat BM-MSCs) into osteoblasts was compared. METHODS: Bone marrow cells were isolated from rat's femurs and tibias. Cytotoxic effect of crocin and crocetin was assayed using MTT test and IC50 was calculated from the results. Osteogenic ability of crocin and crocetin at non-toxic concentrations has been evaluated and compared to osteogenic standard medium after 7 and 21 days, using alizarin red (ALZ) staining and alkaline phosphatase (ALP) activity. Furthermore, ALP mRNA expression has been analyzed by real time RT-PCR. RESULTS: Crocetin showed more cytotoxic effect on stem cells compared to crocin. Non-toxic concentrations (12.5, 25 and 50 µM) were selected for other experiments. Crocin and crocetin (25 µM) increased ALZ intensity (4.2 ±â€¯0.12 and 3.8 ±â€¯0.16 folds, respectively), ALP activity (46.4 ±â€¯5.8 and 43.2 ±â€¯1.9 folds, respectively) and ALP mRNA expression (14.27 ±â€¯1.98 and 8.4 ±â€¯1.17 folds, respectively) in MSCs after day 21 compared to negative control. Although, crocin was more effective than crocetin, but this difference was not significant. CONCLUSION: According to these findings, crocin and crocetin could effectively enhance osteogenic differentiation of MSCs and can be considered as safe therapeutic agents in clinical applications.

miR-126 as a Therapeutic Agent for Diabetes Mellitus.

Diabetes mellitus (DM) is a metabolic disorder which is characterized by inappropriate hyperglycemia. It is becoming an epidemic disease in developing countries. Diabetic patients are frequently afflicted with a vascular dysfunction and wound healing defect. In spite of intense investigations, over the past 2-3 decades, optimal treatment options and related mechanisms are still unclear. MicroRNAs (miRNAs) are small noncoding RNAs considered as regulators of a vast number of biological processes including endothelial cell function controlling molecular signaling pathways in diabetic pathogenesis. Down regulation of microRNA-126 (miR-126) which may regulate angiogenesis and vascular integrity plays a significant role in the pathogenesis and complications of DM. This paper discusses the potential application of miR-126 as a novel therapeutic agent capable of reducing diabetic vascular complications in different types of DM based on the up-to-date reports.