Evaluation of In vivo Bioactivity of a Mutated Streptokinase

 Background: Immunogenicity of Streptokinase, as a thrombolytic drug, has limited its clinical use. Elimination of the amino acid residues that are responsible for immunogenicity while don’t affect the bioactivity of streptokinase is worthy. Recently, we modified the streptokinase through the elimination of 42 amino acids from its’ C-terminal and assessed its bioactivity in vitro. In this study, bioactivity of the mutated-streptokinase determined and compared with those of commercially available streptokinase (Heberkinase) in rabbits with induced blood clot.Materials and Methods: . Recombinant mutated streptokinase was purified and its lipopolysaccharide  contained  remove and evaluated by LAL test. Thrombolytic activity of drug was evaluated by rabbit jugular vein as in vivo thrombosis model. The thrombolytic property of the drug was evaluated with determining of D-dimer in plasma.Results:. The results showed in vivo bioactivity of both truncated and commercial streptokinase (p<0.05). This study showed an important influence of the 42 amino acids of C-terminal in bioactivity of the streptokinase.Conclusion: Clinical use of the r-streptokinase requires more modification to restore its’ activity in vivo. This product may be a promising choice for clinical use after confirmation of its stability and non-immunogenicity

Biological Response of Biphasic Hydroxyapatite/Tricalcium Phosphate Scaffolds Intended for Low Load-Bearing Orthopaedic Applications:

In this study, a calcium phosphate scaffold of hydroxyapatite (HAp) and dicalcium phosphate dihydrate (DCPD) for application in osteoconductive and osteoinductive scaffolds was synthesized and characterized. The important note is that the prepared composites converted to HAp/tricalcium phosphate (TCP) after heat-treatment. This class of composites is interesting because porous HAp/TCP generally degrade more rapid than HAp due to the increased resorption rate of TCP. According to the obtained results, the values of elastic modulus, compressive strength and density of the samples reduced with increasing the percentage of the DCPD phase. It is worth mentioning that the mechanical properties of the prepared samples were near the natural compact bone. The samples were examined in vitro to confirm the apatite forming ability of the composites. Also, in vivo examination in a rabbit model was employed. After fully observation it was concluded that new bone formed on the pore walls, as osteoids and osteoclasts were evident two months postoperatively. Based on the obtained results, the prepared scaffolds seem to be a promising biomaterial for low weight bearing orthopaedic applications

Antibacterial smart hydrogels: New hope for infectious wound management

Millions of people die annually due to uncured wound infections. Healthcare systems incur high costs to treat wound infections. Tt is predicted to become more challenging due to the rise of multidrug-resistant conditions. During the last decades, smart antibacterial hydrogels could attract attention as a promising solution, especially for skin wound infections. These antibacterial hydrogels are termed 'smart' due to their response to specific physical and chemical environmental stimuli. To deliver different drugs to particular sites in a controlled manner, various types of crosslinking strategies are used in the manufacturing process. Smart hydrogels are designed to provide antimicrobial agents to the infected sites or are built from polymers with inherent disinfectant properties. This paper aims to critically review recent pre-clinical and clinical advances in using smart hydrogels against skin wound infections and propose the next best thing for future trends. For this purpose, an introduction to skin wound healing and disease is presented and intelligent hydrogels responding to different stimuli are introduced. Finally, the most promising investigations are discussed in their related sections. These studies can pave the way for producing new biomaterials with clinical applications

3D protein-based bilayer artificial skin for guided scarless healing of full-thickness burn wounds in vivo

Severe burn injuries can lead to delay in healing and devastating scar formation. Attempts are made to develop a suitable skin substitute for scarless healing of such skin wounds. Currently, there is no effective strategy yet for a complete scarless healing after the thermal injuries. In our recent work we fabricate and evaluated a 3D protein-based artificial skin made from decellularized human amniotic membrane (AM) and electrospun nanofibrous silk fibroin (ESF) in vitro. We also characterize both biophysical and cell culture investigation to establish in vitro performance of the developed bilayer scaffolds. In this report we evaluate finally about the appropriate utility of this fabricated bi-layered artificial skin in vivo with particular reference to healing and scar formation due to biochemical and biomechanical complexities of the skin. For this work. AM, AM/ESF alone or seeded with adipose tissue-derived mesenchymal stem cells (AT-MSCs) are implanted to full thickness burn wounds in mice. The healing efficacy and scar formation are evaluated at 7, 14 and 28 days post-implantation in vivo. Our data reveal that ESF accelerates wound healing process through early recruitment of inflammatory cells such as macrophages into the defective site, as well as up-regulation of angiogenic factors from the AT-MSCs and facilitation of remodeling phase. In vivo application of the prepared AM/ESF membrane seeded with the AT-MSCs reduces significantly the post-burn scars. The in vivo data suggest that the potential applications of the AM/ESF bi-layered artificial skin may be considered as a clinically translational product with stem cells to guide scarless healing of sever burn injuries

Antimicrobial peptides-loaded smart chitosan hydrogel: Release behavior and antibacterial potential against antibiotic resistant clinical isolates

In this study, we synthesized thermo -responsive chitosan (TCTS) hydrogels, and loaded with different concentrations of antimicrobial peptide (AMP) (0, 4, 8 and 16 µg.ml - 1 ) to fabricate an antibacterial wound dressing against resistant clinical isolates. Physico -chemical properties, release behavior, cytobiocompatibility and antibacterial activity of the AMP -TCTS hydrogels against standard strain and resistant Acinetobacter baumannii were fully determined in vitro. The TCTS -40% β -glycerolphosphate hydrogels showed a gelation time of 15 min at 37 °C. 80% weight loss at day 35 with no changes in pH value was observed. AMP -TCTS hydrogels showed a burst release of AMP (around 40%) at day 1, and a controlled release up to day 7. A dramatic water uptake was observed at first 4 h, and then continued for 10 h in a steady manner. All the AMP -TCTS hydrogels showed excellent cytobiocompatibility for human fibroblasts. The TCTS showed no antibacterial activity against both standard strain and clinical isolates. All the AMP - TCTS hydrogels had strong antibacterial activity against standard strains, but only 16 µg.ml - 1 showed antibacterial behavior against resistant A. baumannii . Our results strongly suggest the 16 µg.ml - 1 AMP -TCTS hydrogel as a n excellent antibacterial wound dressing against resistant A. baumannii , and now promises to proceed with pre -clinical investigations

Organic Montmorillonite Intercalated Nano-composites Prevent Post-Surgical Associated Infections

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In vitro spermatogenesis in artificial testis: current knowledge and clinical implications for male infertility

Men’s reproductive health exclusively depends on the appropriate maturation of certain germ cells known as sperm. Certain illnesses, such as Klinefelter syndrome, cryptorchidism, and syndrome of androgen insensitivity or absence of testis maturation in men, resulting in the loss of germ cells and the removal of essential genes on the Y chromosome, can cause non-obstructive azoospermia. According to laboratory research, preserving, proliferating, differentiating, and transplanting spermatogonial stem cells or testicular tissue could be future methods for preserving the fertility of children with cancer and men with azoospermia. Therefore, new advances in stem cell research may lead to promising therapies for treating male infertility. The rate of progression and breakthrough in the area of in vitro spermatogenesis is lower than that of SSC transplantation, but newer methods are also being developed. In this regard, tissue and cell culture, supplements, and 3D scaffolds have opened new horizons in the differentiation of stem cells in vitro, which could improve the outcomes of male infertility. Various 3D methods have been developed to produce cellular aggregates and mimic the organization and function of the testis. The production of an artificial reproductive organ that supports SSCs differentiation will certainly be a main step in male infertility treatment

Effect of Co-administration of Bumetanide and Phenobarbital on Seizure Attacks in Temporal Lobe Epilepsy

Introduction: The resistance of temporal lobe epilepsy to classic drugs is thought to be due to disruption in the excitation/inhibition of this pathway. Two chloride transporters, NKCC1 and KCC2, are expressed differently for the excitatory state of Gamma-Amino Butyric Acid (GABA). The present study explored the effect of bumetanide as a selective NKCC1 inhibitor either alone or in combination with the phenobarbital in the pilocarpine model of epilepsy.  Methods: An animal model of Status Epilepticus (SE) was induced with pilocarpine in Wistar male rats followed by phenobarbital and or bumetanide or saline administration for 45 days after the induction of SE by Intraperitoneal (IP) injection. The rats were monitored, their behavior was recorded, and after 24 hours they were sacrificed to study the expression of NKCC1 and KCC2 using real time PCR. Results: The data showed that the effects of a combination of bumetanide with phenobarbital on frequency rate and duration of seizure attack were more than those of the phenobarbital alone. In addition, in the bumetanide and combined treatment groups, NKCC1 expression decreased significantly, compared with untreated epileptic animals. A delayed decrement in NKCC1/KCC2 expression ratio after bumetanide application was also observed. Conclusion: The combination of bumetanide with phenobarbital increases the inhibition of SE and maximizes the potential of GABA signaling pathway, and can be considered as an effective therapeutic strategy in patients with epilepsy

Human Olfactory Mucosa Stem Cells Delivery Using a Collagen Hydrogel: As a Potential Candidate for Bone Tissue Engineering

For bone tissue engineering, stem cell-based therapy has become a promising option. Recently, cell transplantation supported by polymeric carriers has been increasingly evaluated. Herein, we encapsulated human olfactory ectomesenchymal stem cells (OE-MSC) in the collagen hydrogel system, and their osteogenic potential was assessed in vitro and in vivo conditions. Collagen type I was composed of four different concentrations of (4 mg/mL, 5 mg/mL, 6 mg/mL, 7 mg/mL). SDS-Page, FTIR, rheologic test, resazurin assay, live/dead assay, and SEM were used to characterize collagen hydrogels. OE-MSCs encapsulated in the optimum concentration of collagen hydrogel and transplanted in rat calvarial defects. The tissue samples were harvested after 4- and 8-weeks post-transplantation and assessed by optical imaging, micro CT, and H&E staining methods. The highest porosity and biocompatibility were confirmed in all scaffolds. The collagen hydrogel with 7 mg/mL concentration was presented as optimal mechanical properties close to the naïve bone. Furthermore, the same concentration illustrated high osteogenic differentiation confirmed by real-time PCR and alizarin red S methods. Bone healing has significantly occurred in defects treated with OE-MSCs encapsulated hydrogels in vivo. As a result, OE-MSCs with suitable carriers could be used as an appropriate cell source to address clinical bone complications

Coculture of adipose-derived mesenchymal stem cells/macrophages on decellularized placental sponge promotes differentiation into the osteogenic lineage

BACKGROUND: Several factors like three-dimensional microstructure, growth factors, cytokines, cell-cell communication, and coculture with functional cells can affect the stem cells behavior and differentiation. The purpose of this study was to investigate the potential of decellularized placental sponge as adipose-derived mesenchymal stem cells (AD-MSCs) and macrophage coculture systems, and guiding the osteogenic differentiation of stem cells. METHODS: The decellularized placental sponge (DPS) was fabricated, and its mechanical characteristics were evaluated using degradation assay, swelling rate, pore size determination. Its structure was also investigated using hematoxylin and eosin staining and scanning electron microscopy. Mouse peritoneal macrophages and AD-MSCs were isolated and characterized. The differentiation potential of AD-MSCs co-cultured with macrophages was evaluated by RT-qPCR of osteogenic genes on the surface of DPS. The in vivo biocompatibility of DPS was determined by subcutaneous implantation of scaffold and histological evaluations of the implanted site. RESULTS: The DPS had 67% porosity with an average pore size of 238 μm. The in vitro degradation assay showed around 25% weight loss during 30 days in PBS. The swelling rate was around 50% during 72 hours. The coculture of AD-MSCs/macrophages on the DPS showed a significant upregulation of four differentiation osteogenic lineage genes in AD-MSCs on days 14 and 21 and a significantly higher mineralization rate than the groups without DPS. Subcutaneous implantation of DPS showed in vivo biocompatibility of scaffold during 28 days follow up. CONCLUSIONS: Our findings suggest the decellularized placental sponge as an excellent bone substitute providing a naturally derived matrix substrate with biostructure close to the natural bone that guided differentiation of stem cells toward bone cells and a promising coculture substrate for crosstalk of macrophage and mesenchymal stem cells in vitro