Suppression of SOCS3 expression in macrophage cells: Potential application in diabetic wound healing.

Impaired polarization of M1 to M2 macrophages has been reported in diabetic wounds. We aimed to improve this polarization by down-regulation of expression of the "Suppressor of Cytokine Signaling 3" (SOCS3) gene in macrophages. Two oligodeoxynucleotide (ASO) sequences were designed against SOC3 mRNA and were loaded to mannosylated-polyethyleneimine (Man-PEI). The optimum N/P ratio for Man-PEI-ASO was determined to be 8 based on loading efficiency, particle size, zeta potential, cellular uptake and cytotoxicity assay. pH stability of ASO in Man-PEI-ASO and its protection from DNase I was confirmed. After in vitro treatment of macrophages with Man-PEI-ASO, SOCS3 was downregulated, SOCS1 upregulated, and SOCS1/SOCS3 ratio increased. Also, expressions of macrophage markers of M2 (IL-10, Arg1, CD206) increased and those of M1 (IL-1ß, NOS2, CD68) decreased, and secretion of pro-inflammatory cytokines (TNF-α and IL-1ß) decreased while that of anti-inflammatory cytokine IL-4 increased. All suggested a polarization into M2 phenotype. Finally, the Man-PEI-ASO was loaded in hydrogel and applied to a diabetic wound model in mice. It improved the healing to the level observed in non-diabetic wounds. We show that using antisense sequences against SOC3 mRNA, macrophage polarization could be directed into the M2 phenotype and healing of diabetic wound could be highly improved.

Investigating the effect of poly (ɛ-caprolactone) nanofibers scaffolds with random, unidirectionally, and radially aligned morphologies on the Fibroblast cell's attachment and growth behavior.

In the last decade, significant progress in tissue engineering, repairing, and replacing organs has been achieved. The design and production of scaffolds for tissue engineering are one of the main areas which have attracted the researcher's interest. In this regard, electrospinning is one of the most popular methods of nanoscale scaffold similar to extracellular matrix production. This paper reports the fabrication of scaffolds consisting of radially aligned PCL nanofibers by utilizing a collector composed of a central point electrode and a peripheral ring electrode. The chemical and physical properties were compared using SEM, FTIR, XRD, and DSC experiments, as well as biological performance using the MTT method and cell morphology with nanofibers with random and unidirectionally morphology. Results of this study showed greater physical and biological properties for radially aligned nanofibers which make them an excellent candidate for wound healing applications due to the guided cell growth on this type of nanofiber.

Oxidized carboxymethyl cellulose/gelatin in situ gelling hydrogel for accelerated diabetic wound healing: Synthesis, characterization, and in vivo investigations.

Diabetic wounds are chronic wounds that are currently affecting many patient's quality of life. These wounds are challenging because of the impaired healing cycle and harsh environment. In this study in situ gelling hydrogels based on oxidized carboxymethyl cellulose (OCMC) and gelatin (Gel) were used to hasten the healing rate due to their ease of application. The suggested system in this work is synthesized from entirely natural renewable biomaterials to not only achieve the best biocompatibility and biodegradability but also to develop a sustainable product. The rheological studies showed that the hydrogel is turned into a gel after about 30 s of the mixing process. Moreover, the hydrogel can absorb about ten times its weight, keeping the wound hydrated. In vitro biological investigations indicated optimal biocompatibility, antibacterial, and antioxidant activity for faster tissue regeneration. This product was tested in vivo on normal rats and diabetic mice models to treat full-thickness incisional wounds. Results showed that the OCMC-Gel hydrogel is able to hasten the healing rate in both non-diabetic and diabetic wounds. Pathological examinations of the regenerated skin tissue revealed that the OCMC-Gel treated groups developed much more than the control group.

The Effect of Rainbow Trout (Oncorhynchus mykiss) Collagen Incorporated with Exo-Polysaccharides Derived from Rhodotorula mucilaginosa sp. on Burn Healing.

Burn is one of the physically debilitating injuries that can be potentially fatal; therefore, providing appropriate coverage in order to reduce possible mortality risk and accelerate wound healing is mandatory. In this study, collagen/exo-polysaccharide (Col/EPS 1-3%) scaffolds are synthesized from rainbow trout (Oncorhynchus mykiss) skins incorporated with Rhodotorula mucilaginosa sp. GUMS16, respectively, for promoting Grade 3 burn wound healing. Physicochemical characterizations and, consequently, biological properties of the Col/EPS scaffolds are tested. The results show that the presence of EPS does not affect the minimum porosity dimensions, while raising the EPS amount significantly reduces the maximum porosity dimensions. Thermogravimetric analysis (TGA), FTIR, and tensile property results confirm the successful incorporation of the EPS into Col scaffolds. Furthermore,the biological results show that the increasing EPS does not affect Col biodegradability and cell viability, and the use of Col/EPS 1% on rat models displays a faster healing rate. Finally, histopathological examination reveals that the Col/EPS 1% treatment accelerates wound healing, through greater re-epithelialization and dermal remodeling, more abundant fibroblast cells and Col accumulation. These findings suggest that Col/EPS 1% promotes dermal wound healing via antioxidant and anti-inflammatory activities, which can be a potential medical process in the treatment of burn wounds.

Fabrication and characterization of bilayer scaffolds made of decellularized dermis/nanofibrous collagen for healing of full-thickness wounds.

Skin tissue engineering has progressed from simple wound dressings to biocompatible materials with desired physico-chemical properties that can deliver regenerative biomolecules. This study describes using a novel biomimetic hybrid scaffold of decellularized dermis/collagen fibers that can continuously deliver stromal cell-derived factor-1 alpha (SDF-1α) for skin regeneration. In diabetic rat models, the idea that sustained SDF-1α infusion could increase the recruitment of CXCR4-positive cells at the injury site and improve wound regeneration was investigated. The morphology of the scaffold, its biocompatibility, and the kinetics of SDF-1 release were all assessed. SDF-1α was successfully incorporated into collagen nanofibers, resulting in a 200-h continuous release profile. The microscopic observations exhibited that cells are attached and proliferated on proposed scaffolds. As evaluated by in vivo study and histological examination, fabricated scaffold with SDF-1α release capacity exhibited a remarkably more robust ability to accelerate wound regeneration than the control group. Besides, the SDF-1α-loaded scaffold demonstrated functional effects on the proliferation and recruitment of CD31 and CXCR4-positive cells in the wound bed. Additionally, no adverse effects such as hyperplasia or scarring were found during the treatment period. It may be concluded that the fabricated hybrid scaffold based on natural polymer opens up a new option for topical administration of bioactive molecules. We believe the SDF-1α-loaded hybrid scaffold has promise for skin tissue engineering.

Fabrication and investigating in vivo wound healing property of coconut oil loaded nanofiber/hydrogel hybrid scaffold.

Obtaining a sustainable drug delivery system is a challenging issue in biomedical science. This became even more important in the wound regeneration process due to its long treatment process. In this study, the calcium alginate (CaAlg) hydrogel is coated on the surface of polycaprolactone (PCL)/gelatin (Gel) nanofibers containing coconut oil (CO) using the impregnation method. The physical, chemical, and morphological properties of produced samples are investigated using different characterization techniques to verify the influence of hydrogel. Water contact angle, swelling ratio, and water vapor permeability measurements are used to evaluate the effect of hydrogel on the hydrophilicity of the proposed system. The cell viability test showed that the nanocomposite hydrogel is biocompatible and could improve wound healing. According to drug release studies, hydrogel addition to the nanofiber system plays an essential role in controlling CO release rate in the first 250 h. In vivo studies also indicated faster skin regeneration.

Microorganism-derived biological macromolecules for tissue engineering.

According to literature, certain microorganism productions mediate biological effects. However, their beneficial characteristics remain unclear. Nowadays, scientists concentrate on obtaining natural materials from live creatures as new sources to produce innovative smart biomaterials for increasing tissue reconstruction in tissue engineering and regenerative medicine. The present review aims to introduce microorganism-derived biological macromolecules, such as pullulan, alginate, dextran, curdlan, and hyaluronic acid, and their available sources for tissue engineering. Growing evidence indicates that these materials can be used as biological material in scaffolds to enhance regeneration in damaged tissues and contribute to cosmetic and dermatological applications. These natural-based materials are attractive in pharmaceutical, regenerative medicine, and biomedical applications. This study provides a detailed overview of natural-based biomaterials, their chemical and physical properties, and new directions for future research and therapeutic applications.

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.

Synthesis and Characterization of Exopolysaccharide Encapsulated PCL/Gelatin Skin Substitute for Full-Thickness Wound Regeneration.

Loss of skin integrity can lead to serious problems and even death. In this study, for the first time, the effect of exopolysaccharide (EPS) produced by cold-adapted yeast R. mucilaginosa sp. GUMS16 on a full-thickness wound in rats was evaluated. The GUMS16 strain's EPS was precipitated by adding cold ethanol and then lyophilized. Afterward, the EPS with polycaprolactone (PCL) and gelatin was fabricated into nanofibers with two single-needle and double-needle procedures. The rats' full-thickness wounds were treated with nanofibers and Hematoxylin and eosin (H&E) and Masson's Trichrome staining was done for studying the wound healing in rats. Obtained results from SEM, DLS, FTIR, and TGA showed that EPS has a carbohydrate chemical structure with an average diameter of 40 nm. Cell viability assessments showed that the 2% EPS loaded sample exhibits the highest cell activity. Moreover, in vivo implantation of nanofiber webs on the full-thickness wound on rat models displayed a faster healing rate when EPS was loaded into a nanofiber. These results suggest that the produced EPS can be used for skin tissue engineering applications.

Cellulose nanocrystal effect on crystallization kinetics and biological properties of electrospun polycaprolactone.

Mechanical properties of tissue engineering nanofibrous scaffolds are of importance because they not only determine their ease of application, but also influence the environment for cell growth and proliferation. Cellulose nanocrystals (CNCs) are natural renewable nanoparticles that have been widely used for manipulating nanofibers' mechanical properties. In this article, cellulose nanoparticles were incorporated into poly(caprolactone) (PCL) solution, and composite nanofibers were produced. Ozawa-Flynn-Wall (OFW) methodology and X-ray diffraction were used to investigate the effect of CNC incorporation on PCL crystalline structure and its biological properties. Results showed that CNC incorporation up to 1% increases the crystallization activation energy and reduces the crystal volume, while these factors remain constant above this critical concentration. MTT assay and microscopic images of seeded cells on the nanofiber scaffolds indicated increased cell growth on the samples containing CNC. This behavior could be attributed to their greater hydrophilicity, which was confirmed using parallel exponential kinetics (PEK) model fitting to results obtained from dynamic vapor sorption (DVS) studies. Superior performance of CNC containing samples was also confirmed by in vivo implantation on full-thickness wounds. The wound area faded away more rapidly in these samples. H&E and Masson's trichrome staining showed better regeneration and more developed tissues in wounds treated with PCL-CNC1% nanofibers.

Cinnamon extract loaded electrospun chitosan/gelatin membrane with antibacterial activity.

This study develops chitosan/gelatin nanofiber membranes with sustained release capacity to prevent infection by delivering cinnamon extract (CE) in the implanted site. The effects of the incorporation of CE content (2-6%) on the properties of the nanofibers were evaluated. Morphological studies using SEM indicated that loading the extract did not affect the average diameter of nanofiber mats, which remained around 140-170 nm. TGA and FTIR spectroscopy results confirmed successful CE loading. Furthermore, the results showed that incorporating extract into the nanofibers enhanced their degradation behavior, antibacterial activity, and biocompatibility. Cultured cells attached to and proliferate on the nanofiber membrane with high cell viability capacity until the CE content reached 4%. The extract release profile consisted of a burst release in the first 6 h, followed by a controlled release in the next 138 h. Therefore, CE loaded chitosan/gelatin nanofiber is an excellent construct for biomedical applications.

Fabricating alginate/poly(caprolactone) nanofibers with enhanced bio-mechanical properties via cellulose nanocrystal incorporation.

In this research, cellulose nanocrystal (CNC) was synthesized from cotton waste using controlled hydrolysis against 64 % (w/w) sulfuric acid solution. The produced nanoparticles were then characterized using FTIR, XRD, TGA, and DLS analyses. Biaxial electrospinning technique was used to produce CNC incorporated PCL-PVA/NaAlg nanofibers. The sodium alginate portion was then crosslinked via submerging the samples in calcium chloride aqueous solution. The CNC incorporated and crosslinked sample was characterized using SEM, FTIR, and TGA techniques. Results confirmed the presence of CNC nanoparticles and alginate crosslinking reaction. Mechanical studies showed that CNC incorporation increases the tensile modulus by 65 %. Also, the crosslinked samples exhibited an increase in elongation at break. Water contact angle studies suggested that CNC incorporation and crosslinking improves nanofiber hydrophilicity. Cell viability of more than 90 % was observed in CNC incorporated PCL-CaAlg nanofibers. Also, SEM images of cells on nanofiber scaffolds showed better cell growth and attachment in PCL-CaAlg-CNC samples.

Investigation of morphological, mechanical and biological properties of cellulose nanocrystal reinforced electrospun gelatin nanofibers.

Incorporation of nanoparticles into biomaterials is of interest due to the high demand for medical devices with enhanced mechanical properties. In this study, cellulose nanocrystals (CNC) were incorporated in electrospun gelatin nanofibers at various loadings (0-15% w/w) and characterized using XRD, TGA, TEM, SEM, FTIR, and tensile tests. Results obtained from TGA and tensile properties indicate that CNC were agglomerated at loadings exceeding 5%; however, TEM showed excellent dispersion of nanoparticles at 5% CNC. A slight increase in biodegradability of crosslinked gelatin nanofibers was observed with CNC incorporation. MTT cytotoxicity, fluorescent staining, and SEM images showed that CNC had no significant effect on cell growth and proliferation.

Drug release and biodegradability of electrospun cellulose nanocrystal reinforced polycaprolactone.

In this paper, high molecular weight cellulose was used as the starting material for the synthesis of cellulose nanocrystal (CNC). Different analysis techniques such as FTIR, XRD, TGA, DLS, and AFM were used to characterize CNC synthesis. The synthesized CNC was incorporated in polycaprolactone solution and nanofibers were prepared under different conditions. Production conditions were optimized based on the diameter of nanofibers using response surface methodology (RSM). Based on our results, the optimal condition is electrospinning of 16% PCL polymer solution at 17 kV and a 0.9 ml/h feed rate, which yields nanofibers with a diameter of 233 nm. The effects of CNC content on morphological, mechanical and thermal properties were investigated. Results also showed that CNC incorporation in PCL nanofibers enhances biodegradability. SEM, DSC, tensile, and biodegradability results showed that the nanofibers prepared from PCL solution containing 1% CNC have optimal mechanical and degradation behaviors. We also studied and modeled release of tetracycline from nanofiber mats, based on the assumption of rate limiting diffusion from the nanofibers, with a fraction of release delayed by drug sequestration. Results showed that the final drug release is decreased in CNC-incorporated nanofibers.

A new cellulose purification approach for higher degree of polymerization: Modeling, optimization and characterization.

Degree of polymerization (DP) is an important factor which is affected by purification process. In this study, a new purification process is proposed in which cellulose DP is preserved. Response surface methodology (RSM) was used for optimizing the purification conditions. Purification process of biomass at 100°C in 10g/L sodium hydroxide and 30g/L sodium dithionite, is reported as the optimum condition of this treatment. DP, purity, weight reduction and yellowness index were 6012, 98.10%, 8.46% and 25.22 respectively. TGA, IR, XRD and SEM techniques were used to compare both this new approach and conventional purification treatments. The results showed that this proposed purification process can produce cellulose with higher degree of polymerization compare to the conventional method.

Ultrasonic mediated production of carboxymethyl cellulose: Optimization of conditions using response surface methodology.

In the present research the optimization of ultrasound-mediated production of carboxymethyl cellulose under microwave irradiation, towards achieving reduction of chemicals, time of reaction and energy was carried out. Cellulose was extracted and treated by environmentally friendly chlorine free bleaching method using hydrogen peroxide. Produced alpha-cellulose was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric/differential thermal analysis (TG/DTA). Response Surface Methodology (RSM) was used to optimize the preparation of carboxymethyl cellulose (CMC). Highest degree of substitution 0.74 was obtained at 240 W ultrasonic power for 37 min followed by etherification at 490 W microwave power for 12 min. Results show that the preparation of CMC from cotton linter using ultrasound and microwave energy can reduce the processing time, chemicals and energy consumption. Additionally, X-ray analysis shows that the ultrasonic energy is able to break cellulose crystals into smaller parts compared to other methods. SEM photographs showed that this treatment is able to remove impurities from raw material.