Reinforcing decellularized small intestine submucosa with cellulose acetate nanofibrous and silver nanoparticles as a scaffold for wound healing applications.

BACKGROUND: The formation of chronic wounds accounts for considerable costs in health care systems. Despite the several benefits of decellularized small intestinal submucosa (SIS) as an appropriate scaffold for different tissue regeneration, it has shortcomings such as lack of antibacterial features and inappropriate mechanical properties for skin tissue regeneration. We aimed to examine the efficacy and safety of decellularized SIS scaffold enhanced with cellulose acetate (CA) and silver (Ag) nanoparticles (NPs) for healing full-thickness wounds. METHODS AND RESULTS: The scaffolds were prepared by decellularizing bovine SIS and electrospinning CA/Ag nanoparticles and characterized using a transmission electron microscope (TEM), scanning electron microscope (SEM), tensile testing, and X-ray diffraction. In vivo evaluations were performed using full-thickness excisions covered with sterile gauze as the control group, SIS, SIS/CA, and SIS/CA/Ag scaffolds on the dorsum of twenty male Wistar rats divided into four groups randomly with 21-days follow-up. All in vivo specimens underwent Masson's trichrome (MT) staining for evaluation of collagen deposition, transforming growth factor-ß (TGF-ß) immunohistochemistry (IHC), and Haematoxylin Eosin (H&E) staining. The IHC and MT data were analyzed with the ImageJ tool by measuring the stained area. The TEM results revealed that Ag nanoparticles are successfully incorporated into CA nanofibers. Assessment of scaffolds hydrophilicity demonstrated that the contact angle of SIS/CA/Ag scaffold was the lowest. The in vivo results indicated that the SIS/CA/Ag scaffold had the most significant wound closure. H&E staining of the in vivo specimens showed the formation of epidermal layers in the SIS/CA/Ag group on day 21. The percentage of the stained area of MT and TGF-ß IHC staining's was highest in the SIS/CA/Ag group. CONCLUSION: The decellularized SIS/CA/Ag scaffolds provided the most significant wound closure compared to other groups and caused the formation of epidermal layers and skin appendages. Additionally, the collagen deposition and expression of TGF-ß increased significantly in SIS/CA/Ag group.

The clinical impact of mRNA therapeutics in the treatment of cancers, infections, genetic disorders, and autoimmune diseases.

mRNA-based therapeutics have revolutionized medicine and the pharmaceutical industry. The recent progress in the optimization and formulation of mRNAs has led to the development of a new therapeutic platform with a broad range of applications. With a growing body of evidence supporting the use of mRNA-based drugs for precision medicine and personalized treatments, including cancer immunotherapy, genetic disorders, and autoimmune diseases, this emerging technology offers a rapidly expanding category of therapeutic options. Furthermore, the development and deployment of mRNA vaccines have facilitated a prompt and flexible response to medical emergencies, exemplified by the COVID-19 outbreak. The establishment of stable and safe mRNA molecules carried by efficient delivery systems is now available through recent advances in molecular biology and nanotechnology. This review aims to elucidate the advancements in the clinical applications of mRNAs for addressing significant health-related challenges such as cancer, autoimmune diseases, genetic disorders, and infections and provide insights into the efficacy and safety of mRNA therapeutics in recent clinical trials.

Regenerative potential of mesenchymal stromal cells in wound healing: unveiling the influence of normoxic and hypoxic environments.

The innate and adaptive immune systems rely on the skin for various purposes, serving as the primary defense against harmful environmental elements. However, skin lesions may lead to undesirable consequences such as scarring, accelerated skin aging, functional impairment, and psychological effects over time. The rising popularity of mesenchymal stromal cells (MSCs) for skin wound treatment is due to their potential as a promising therapeutic option. MSCs offer advantages in terms of differentiation capacity, accessibility, low immunogenicity, and their central role in natural wound-healing processes. To accelerate the healing process, MSCs promote cell migration, angiogenesis, epithelialization, and granulation tissue development. Oxygen plays a critical role in the formation and expansion of mammalian cells. The term "normoxia" refers to the usual oxygen levels, defined at 20.21 percent oxygen (160 mm of mercury), while "hypoxia" denotes oxygen levels of 2.91 percent or less. Notably, the ambient O2 content (20%) in the lab significantly differs from the 2%-9% O2 concentration in their natural habitat. Oxygen regulation of hypoxia-inducible factor-1 (HIF-1) mediated expression of multiple genes plays a crucial role in sustaining stem cell destiny concerning proliferation and differentiation. This study aims to elucidate the impact of normoxia and hypoxia on MSC biology and draw comparisons between the two. The findings suggest that expanding MSC-based regenerative treatments in a hypoxic environment can enhance their growth kinetics, genetic stability, and expression of chemokine receptors, ultimately increasing their effectiveness.

Advances in novel strategies for isolation, characterization, and analysis of CTCs and ctDNA.

Over the past decade, the detection and analysis of liquid biopsy biomarkers such as circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) have advanced significantly. They have received recognition for their clinical usefulness in detecting cancer at an early stage, monitoring disease, and evaluating treatment response. The emergence of liquid biopsy has been a helpful development, as it offers a minimally invasive, rapid, real-time monitoring, and possible alternative to traditional tissue biopsies. In resource-limited settings, the ideal platform for liquid biopsy should not only extract more CTCs or ctDNA from a minimal sample volume but also accurately represent the molecular heterogeneity of the patient's disease. This review covers novel strategies and advancements in CTC and ctDNA-based liquid biopsy platforms, including microfluidic applications and comprehensive analysis of molecular complexity. We discuss these systems' operational principles and performance efficiencies, as well as future opportunities and challenges for their implementation in clinical settings. In addition, we emphasize the importance of integrated platforms that incorporate machine learning and artificial intelligence in accurate liquid biopsy detection systems, which can greatly improve cancer management and enable precision diagnostics.

Advances in TEER measurements of biological barriers in microphysiological systems.

Biological barriers are multicellular structures that precisely regulate the transport of ions, biomolecules, drugs, cells, and other organisms. Transendothelial/epithelial electrical resistance (TEER) is a label-free method for predicting the properties of biological barriers. Understanding the mechanisms that control TEER significantly enhances our knowledge of the physiopathology of different diseases and aids in the development of new drugs. Measuring TEER values within microphysiological systems called organ-on-a-chip devices that simulate the microenvironment, architecture, and physiology of biological barriers in the body provides valuable insight into the behavior of barriers in response to different drugs and pathogens. These integrated systems should increase the accuracy, reproducibility, sensitivity, resolution, high throughput, speed, cost-effectiveness, and reliable predictability of TEER measurements. Implementing advanced micro and nanoscale manufacturing techniques, surface modification methods, biomaterials, biosensors, electronics, and stem cell biology is necessary for integrating TEER measuring systems with organ-on-chip technology. This review focuses on the applications, advantages, and future perspectives of integrating organ-on-a-chip technology with TEER measurement methods for studying biological barriers. After briefly reviewing the role of TEER in the physiology and pathology of barriers, standard techniques for measuring TEER, including Ohm's law and impedance spectroscopy, and commercially available devices are described. Furthermore, advances in TEER measurement are discussed in multiple barrier-on-a-chip system models representing different organs. Finally, we outline future trends in implementing advanced technologies to design and fabricate nanostructured electrodes, complicated microfluidic chips, and membranes for more advanced and accurate TEER measurements.

Advanced models for respiratory disease and drug studies.

The global burden of respiratory diseases is enormous, with many millions of people suffering and dying prematurely every year. The global COVID-19 pandemic witnessed recently, along with increased air pollution and wildfire events, increases the urgency of identifying the most effective therapeutic measures to combat these diseases even further. Despite increasing expenditure and extensive collaborative efforts to identify and develop the most effective and safe treatments, the failure rates of drugs evaluated in human clinical trials are high. To reverse these trends and minimize the cost of drug development, ineffective drug candidates must be eliminated as early as possible by employing new, efficient, and accurate preclinical screening approaches. Animal models have been the mainstay of pulmonary research as they recapitulate the complex physiological processes, Multiorgan interplay, disease phenotypes of disease, and the pharmacokinetic behavior of drugs. Recently, the use of advanced culture technologies such as organoids and lung-on-a-chip models has gained increasing attention because of their potential to reproduce human diseased states and physiology, with clinically relevant responses to drugs and toxins. This review provides an overview of different animal models for studying respiratory diseases and evaluating drugs. We also highlight recent progress in cell culture technologies to advance integrated models and discuss current challenges and present future perspectives.

Evaluation of colonic anastomosis healing using hybrid nanosheets containing molybdenum disulfide (MOS2) scaffold of human placental amniotic membrane and polycaprolactone (PCL) in rat animal model.

Anastomosis is a standard technique following different conditions such as obstruction, tumor, and trauma. Obstruction, adhesion, or anastomosis leakage can be some of its complications. To improve healing and prevent postoperative complications, we design a hybrid scaffold containing acellular human amniotic membranes and polycaprolactone-molybdenum disulfide nanosheets for colon anastomosis. The animal model of colocolonic anastomosis was performed on two groups of rats: control and scaffold. The hybrid scaffold was warped around the anastomosis site in the scaffold group. Samples from the anastomosis site were resected on the third and seventh postoperative days for histopathological and molecular assessments. Histopathologic score and burst pressure had shown significant improvement in the scaffold group. No mortality and anastomosis leakage was reported in the scaffold group. In addition, inflammatory markers were significantly decreased, while anti-inflammatory cytokines were increased in the scaffold group. The result indicates that our hybrid scaffold is a proper choice for colorectal anastomosis repair by declining postoperative complications and accelerating healing.

Thiolate DNAzymes on Gold Nanoparticles for Isothermal Amplification and Detection of Mesothelioma-derived Exosomal PD-L1 mRNA.

Catalytic DNAzymes have been used for isothermal amplification and rapid detection of nucleic acids, holding the potential for point-of-care testing applications. However, when Subzymes (universal substrate and DNAzyme) are tethered to the polystyrene magnetic microparticles via biotin-streptavidin bonds, the residual free Subzymes are often detached from the microparticle surface, which causes a significant degree of false positives. Here, we attached dithiol-modified Subzyme to gold nanoparticle and improved the limit of detection (LoD) by 200 times compared to that using magnetic microparticles. As a proof of concept, we applied our new method for the detection of exosomal programed cell-death ligand 1 (PD-L1) RNA. As the classical immune checkpoint, molecule PD-L1, found in small extracellular vesicles (sEVs, traditionally called exosomes), can reflect the antitumor immune response for predicting immunotherapy response. We achieved the LoD as low as 50 fM in detecting both the RNA homologous to the PD-L1 gene and exosomal PD-L1 RNAs extracted from epithelioid and nonepithelioid subtypes of mesothelioma cell lines, which only takes 8 min of reaction time. As the first application of isothermal DNAzymes for detecting exosomal PD-L1 RNA, this work suggests new point-of-care testing potentials toward clinical translations.

Adipose-derived Stem Cells: Potentials, Availability and Market Size in Regenerative Medicine.

Adipose-derived stem cells (ADSCs) have been described as one of the most potent and accessible human adult stem cells which can be utilized in various therapeutic approaches. Due to the wide variety of cytokines and GFs secreted by them, ADSCs can be used for controlled drug release. These cells can be used for proliferation and differentiation of tissues regardless of survival conditions and immunologic problems. Because of their ability to differentiate into various lineages, ADSCs can be used in musculoskeletal problems, diabetes, heart diseases, obesity, neurologic and nephrogenic diseases, and wound healing, as well as applications in regenerative medicine such as osteogenic, cartilage, tendon, muscle, skin, CNS, cardiac and vascularization, as well as liver and even periodontal regeneration. To maintain the highest viability and efficiency, companies that provide ADSCs should offer the best product quality to gain market share and scientists need to acquire an understanding of sources where they can find the best products available. Therefore, in this article, we have reviewed the available products, companies and the market size currently available for ADSCs. Enormous effort has been made to list the most important trials, products and companies currently existent in the field. To achieve better outcomes in scientific research, there is the need to compare the products available and choose the best option according to desired goals. Thus, this paper provides a valuable reference for those interested in the field of ADSCs and their applications.

Evaluating the safety and efficacy of mesenchymal stem cell-derived exosomes for treatment of refractory perianal fistula in IBD patients: clinical trial phase I.

Background: Exosome administration is a novel medical approach that promises excellent immunomodulatory properties without the conventional side effects of current antitumor necrosis factor drugs and stem cells. This study aimed to assess the safety and efficacy of using mesenchymal stem cell (MSC) exosomes to treat refractory fistulas in patients with inflammatory bowel disease. Methods: MSCs were derived from the umbilical cords and their exosomes were isolated. Five patients with refractory perianal Crohn's disease fistulas with a median age of 35 years (range 31-47 years) were enrolled in the study. Exosome injections were administered in the operating room to patients with refractory fistula (fistulas that are irresponsive to anti-tumor necrosis factor-α administration within 6 months). Six months later, a physical examination, face-to-face interviews, and magnetic resonance imaging were employed to evaluate the therapy responses of patients. Results: The outcomes within 6 months after initiation of therapy showed that four patients had responded to therapy. Three patients who received exosome injections exhibited complete healing, while one reported no improvement and active discharge from the fistula site. In addition, five patients (100%) reported neither systemic nor local adverse effects. Conclusions: Injection of exosomes extracted from MSCs demonstrates safety and a satisfactory therapeutic effect, as evidenced in this and other studies, and may play a significant role in the future treatment of gastrointestinal fistulas.

Advanced Regenerative Medicine Strategies for Treatment of Perianal Fistula in Crohn's Disease.

Regenerative medicine is an emerging therapeutic method that aims to reconstruct tissues and organs. This advanced therapeutic approach has demonstrated great potential in addressing the limitations of medical and surgical procedures for treating perineal fistula in patients with Crohn's disease. Recent developments in stem cell technology have led to a massive good manufacturing practices (GMPs) production of various stem cells, including mesenchymal and embryonic cells, along with induction of pluripotent stem cells to repair damaged tissues in the fistula. The recent advances in separation and purification of exosomes, as biologic nanovesicles carrying anti-inflammatory and regenerative agents, have made them powerful tools to treat this inflammatory disease. Further, tremendous advances in nanotechnology, biomaterials, and scaffold fabrication methods enable tissue engineering methods to synthesize tissue-like structures to assist surgical techniques. This review focuses on advanced regenerative-based methods including stem cell therapy, exosome therapy, and tissue engineering used in the treatment of perianal fistula. Relevant in vitro and in vivo studies and the latest innovations in implementation of regenerative medicine for this disease are also separately reviewed. Additionally, current challenges regarding implementation of g stem cells, exosomes, and tissue engineering methods for bridging the gaps between laboratory findings and clinic application will be discussed.

Advanced bioengineering of male germ stem cells to preserve fertility.

In modern life, several factors such as genetics, exposure to toxins, and aging have resulted in significant levels of male infertility, estimated to be approximately 18% worldwide. In response, substantial progress has been made to improve in vitro fertilization treatments (e.g. microsurgical testicular sperm extraction (m-TESE), intra-cytoplasmic sperm injection (ICSI), and round spermatid injection (ROSI)). Mimicking the structure of testicular natural extracellular matrices (ECM) outside of the body is one clear route toward complete in vitro spermatogenesis and male fertility preservation. Here, a new wave of technological innovations is underway applying regenerative medicine strategies to cell-tissue culture on natural or synthetic scaffolds supplemented with bioactive factors. The emergence of advanced bioengineered systems suggests new hope for male fertility preservation through development of functional male germ cells. To date, few studies aimed at in vitro spermatogenesis have resulted in relevant numbers of mature gametes. However, a substantial body of knowledge on conditions that are required to maintain and mature male germ cells in vitro is now in place. This review focuses on advanced bioengineering methods such as microfluidic systems, bio-fabricated scaffolds, and 3D organ culture applied to the germline for fertility preservation through in vitro spermatogenesis.

Polyethylene glycol triggers the anti-cancer impact of curcumin nanoparticles in sw-1736 thyroid cancer cells.

Curcumin has been recognized as an effective anticancer agent. However, due to its hydrophobic property, the cell absorption is not satisfied. Herein, the curcumin nanoparticles were prepared in the presence of polyethylene glycol 6000 (PEG6000) to reduce its elimination by immune system. For first time, not only the curcumin was encapsulated within the niosome nanoparticles modified by PEG, there are no reports related to the anticancer property of curcumin against thyroid cancers. The nanoparticles was developed and its anticancer was studied on sw-1736 cancer cell line. The nanoparticles were examined by scanning electron microscopy (SEM) and dynamic light scattering (DLS). Also, the release profile of curcumin, the IC50 concentration, the radical amount and the gene expression were evaluated. The optimized nanoparticles showed a diameter of 212 ± 31 nm by SEM and the encapsulation efficiency and loading capacity of 76% and 16.8% respectively. DLS confirmed the polydispersity index (PDI) of 0.596 and the release model was shown a sustained release with the delivery of 68% curcumin after 6 days. Also, the nanoparticles indicated the higher storage stability at 4 °C. After the cell treatment, the apoptotic bodies were appeared and IC50 was obtained as 0.159 mM. Moreover, the generated radicals by the treated cells was 86% after 72 h and the gene pattern indicated the bax/bcl2 ratio of 6.83 confirming the apoptosis effect of the nanoparticles. The results approved the nanoparticles could be suggested as an anticancer drug candidate for thyroid cancers. The encapsulated curcumin within the niosome nanoparticles modified with PEG, could be released and up-taken by the thyroid cancer cell line due to the same hydrophobic property of cell membrane and the niosome particles. The reaction between curcumin and cellular components generates radicals and activates the apoptotic pathway. The corresponding reaction finally makes cell death.

Microfluidic-Based Droplets for Advanced Regenerative Medicine: Current Challenges and Future Trends.

Microfluidics is a promising approach for the facile and large-scale fabrication of monodispersed droplets for various applications in biomedicine. This technology has demonstrated great potential to address the limitations of regenerative medicine. Microfluidics provides safe, accurate, reliable, and cost-effective methods for encapsulating different stem cells, gametes, biomaterials, biomolecules, reagents, genes, and nanoparticles inside picoliter-sized droplets or droplet-derived microgels for different applications. Moreover, microenvironments made using such droplets can mimic niches of stem cells for cell therapy purposes, simulate native extracellular matrix (ECM) for tissue engineering applications, and remove challenges in cell encapsulation and three-dimensional (3D) culture methods. The fabrication of droplets using microfluidics also provides controllable microenvironments for manipulating gametes, fertilization, and embryo cultures for reproductive medicine. This review focuses on the relevant studies, and the latest progress in applying droplets in stem cell therapy, tissue engineering, reproductive biology, and gene therapy are separately evaluated. In the end, we discuss the challenges ahead in the field of microfluidics-based droplets for advanced regenerative medicine.

Electrical stimulation induces differentiation of human cardiosphere-derived cells (hCDCs) to committed cardiomyocyte.

Logistic complexities of heart transplantation embossed the necessity of utilizing novel methods, which enable heart regeneration. Human cardiosphere-derived cells (hCDCs) are taken into consideration as a promising cell resource in cell therapy in recent years. In this study, we designed an electrochemical stimulation system, which sends square pulses to the hCDCs and records their electrical response. Morphology, viability and differentiation of hCDCs are monitored at certain time courses of the treatment. Differentiating hCDCs aligned perpendicularly with respect to the direction of applied electric current, and obtained a spindle-like morphology, while they remained viable. At the same time, specific cardiac marker genes including GATA4, cTnT and α-MHC showed a considerable up-regulation. Our findings confirm that hCDCs differentiate to committed cardiomyocytes when hCDCs receive an electrical energy of 0.06 - 0.12 Wh. This amount of electrical energy could be applied to the stem cells using versatile electrical stimulation patterns via commercially available devices.

Incorporation of SPION-casein core-shells into silk-fibroin nanofibers for cardiac tissue engineering.

Mimicking the structure of extracellular matrix (ECM) of myocardium is necessary for fabrication of functional cardiac tissue. The superparamagnetic iron oxide nanoparticles (SPIONs, Fe3 O4 ), as new generation of magnetic nanoparticles (NPs), are highly intended in biomedical studies. Here, SPION NPs (1 wt%) were synthesized and incorporated into silk-fibroin (SF) electrospun nanofibers to enhance mechanical properties and topography of the scaffolds. Then, the mouse embryonic cardiac cells (ECCs) were seeded on the scaffolds for in vitro studies. The SPION NPs were studied by scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM). SF nanofibers were characterized after incorporation of SPIONs by SEM, TEM, water contact angle measurement, and tensile test. Furthermore, cytocompatibility of scaffolds was confirmed by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. SEM images showed that ECCs attached to the scaffolds with elongated morphologies. Also, the real-time PCR and immunostaining studies approved upregulation of cardiac functional genes in ECCs seeded on the SF/SPION-casein scaffolds including GATA-4, cardiac troponin T, Nkx 2.5, and alpha-myosin heavy chain, compared with the ones in SF. In conclusion, incorporation of core-shells in SF supports cardiac differentiation, while has no negative impact on ECCs' proliferation and self-renewal capacity.

Electrically conductive nanomaterials for cardiac tissue engineering.

Patient deaths resulting from cardiovascular diseases are increasing across the globe, posing the greatest risk to patients in developed countries. Myocardial infarction, as a result of inadequate blood flow to the myocardium, results in irreversible loss of cardiomyocytes which can lead to heart failure. A sequela of myocardial infarction is scar formation that can alter the normal myocardial architecture and result in arrhythmias. Over the past decade, a myriad of tissue engineering approaches has been developed to fabricate engineered scaffolds for repairing cardiac tissue. This paper highlights the recent application of electrically conductive nanomaterials (carbon and gold-based nanomaterials, and electroactive polymers) to the development of scaffolds for cardiac tissue engineering. Moreover, this work summarizes the effects of these nanomaterials on cardiac cell behavior such as proliferation and migration, as well as cardiomyogenic differentiation in stem cells.

Gold nanorods reinforced silk fibroin nanocomposite for peripheral nerve tissue engineering applications.

Nowadays, regenerating peripheral nerves injuries (PNIs) remain a major clinical challenge, which has gained a great attention between scientists. Here, we represent a nanocomposite based on silk fibroin reinforced gold nanorods (SF/GNRs) to evaluate the proliferation and attachment of PC12 cells. The morphological characterization of nanocomposites with transmission electron microscopy (TEM) and Scanning electron microscopy (SEM) showed that the fabricated scaffolds have porous structure with interconnected pores that is suitable for cell adhesion and growth. GNRs significantly improved the poor electrical conductivity of bulk silk fibroin scaffold. Evaluating the morphology of PC12 cells on the scaffold also confirmed the normal morphology of cells with good rate of adhesion. SF/GNRs nanocomposites showed better cellular attachment, growth and proliferation without any toxicity compared with bulk SF scaffold. Moreover, immunostaining studies represented the overexpression of neural specific proteins like nestin and neuron specific enolase (NSE) in the cells cultured on SF/GNRs nanocomposites in comparison to neat SF scaffolds.

Polyethylenimine: A new differentiation factor to endothelial/cardiac tissue.

Among different tissues, endothelial/cardiac types require specific factors to promote myocardial regeneration after occurred injuries. Herein, cardiac stem cells (CSCs) as the major cell population that involved in cardiovascular repair were selected to study the role of polyethyleneimine (PEI) agent on endothelial differentiation. After preparation of electrospun network of PEI with polyacrylonitrile, the related characterizations were carried out including scanning electron microscope (SEM), field-emission SEM, water contact angle, Fourier transform infrared spectroscopy and mechanical properties. Also, the release kinetic of the corresponding agent was studied up to 7 days. The cell differentiation studies were done in the following with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, Real-time polymerase chain reaction and immunostaining method. The whole obtained results approved the higher differentiation of CSCs into endothelial/cardiac cells. Finally, it is recommended that the PEI delivering increases the healing potency of CSCs and accordingly the regeneration speed of damaged cardiovascular tissue would be improved.