Fibroblast Cell Migration Research Articles

In vitro magnetohydrodynamics system for modulating cell migration

Fluid shear stress (FSS) is an important parameter that regulates various cell functions such as proliferation and migration. While there are a number of techniques to generate FSS in vitro, many of them require physical deformation or movement of solid objects to generate the fluid shear, making it difficult to decouple the effects of FSS and mechanical strains. This work describes the development of a non-mechanical means to generate fluid flow and FSS in a 2D in vitro setting. This was accomplished with a magnetohydrodynamic (MHD) pump, which creates liquid flow by generating a Lorentz force through the interaction between an electric field and an orthogonal magnetic field. The MHD pump system presented here consisted of trapezoidal prism-shaped magnets, a pair of platinum electrodes, and a modified petri dish. The system was validated and tested on an in vitro wound model, which is based on analyzing the migration of fibroblast cells through an artificially created scratch on a confluent cell culture surface. Experiments were performed to a control group, an electric field only group, and a group that was subject to fluid flow with the application of both electric field and magnetic field. Results show that fibroblast cells that experienced fluid shear have higher wound closure rate compared to the control group and the electric field only group. The data shows that the MHD pump can be a great tool to study FSS in vitro. Furthermore, due to its fluid flow generation without mechanical force, this system can be adapted and implemented to study the role of FSS and electric field on wound healing in vivo.

Fluro-Protein C-Phycocyanin Docked Silver Nanocomposite Accelerates Cell Migration through NFĸB Signaling Pathway.

Currently, there is a great demand for the development of nanomedicine aided wound tissue regeneration via silver doped nanoceuticals. Unfortunately, very little research is being carried out on antioxidants-doped silver nanometals and their interaction on the signaling axis during the bio-interface mechanism. In this study, c-phycocyanin primed silver nano hybrids (AgcPCNP) were prepared and analyzed for properties such as cytotoxicity, metal decay, nanoconjugate stability, size expansion, and antioxidant features. Fluctuations in the expression of marker genes during cell migration phenomena in in vitro wound healing scenarios were also validated. Studies revealed that physiologically relevant ionic solutions did not exhibit any adverse effects on the nanoconjugate stability. However, acidic, alkali, and ethanol solutions completely denatured the AgcPCNP conjugates. Signal transduction RT2PCR array demonstrated that genes associated with NFĸB- and PI3K-pathways were significantly (p < 0.5%) altered between AgcPCNP and AgNP groups. Specific inhibitors of NFĸB (Nfi) and PI3K (LY294002) pathways confirmed the involvement of NFĸB signaling axes. In vitro wound healing assay demonstrated that NFĸB pathway plays a prime role in the fibroblast cell migration. In conclusion, the present investigation revealed that surface functionalized AgcPCNP accelerated the fibroblast cell migration and can be further explored for wound healing biomedical applications.

Antioxidant, Wound Healing Potential and In Silico Assessment of Naringin, Eicosane and Octacosane.

1. Diabetic chronic wounds, mainly foot ulcers, constitute one of the most common complications of poorly managed diabetes mellitus. The most typical reasons are insufficient glycemic management, latent neuropathy, peripheral vascular disease, and neglected foot care. In addition, it is a common cause of foot osteomyelitis and amputation of the lower extremities. Patients are admitted in larger numbers attributable to chronic wounds compared to any other diabetic disease. In the United States, diabetes is currently the most common cause of non-traumatic amputations. Approximately five percent of diabetics develop foot ulcers, and one percent require amputation. Therefore, it is necessary to identify sources of lead with wound-healing properties. Redox imbalance due to excessive oxidative stress is one of the causes for the development of diabetic wounds. Antioxidants have been shown to decrease the progression of diabetic neuropathy by scavenging ROS, regenerating endogenous and exogenous antioxidants, and reversing redox imbalance. Matrix metalloproteinases (MMPs) play vital roles in numerous phases of the wound healing process. Antioxidant and fibroblast cell migration activity of Marantodes pumilum (MP) crude extract has previously been reported. Through their antioxidant, epithelialization, collagen synthesis, and fibroblast migration activities, the authors hypothesise that naringin, eicosane and octacosane identified in the MP extract may have wound-healing properties. 2. The present study aims to identify the bioactive components present in the dichloromethane (DCM) extract of M. pumilum and evaluate their antioxidant and wound healing activity. Bioactive components were identified using LCMS, HPTLC and GCMS. Excision wound on STZ-induced diabetic rat model, human dermal fibroblast (HDF) cell line and colorimetric antioxidant assays were used to evaluate wound healing and antioxidant activities, respectively. Molecular docking and pkCMS software would be utilised to predict binding energy and affinity, as well as ADME parameters. 3. Naringin (NAR), eicosane (EIC), and octacosane (OCT) present in MP displayed antioxidant action and wound excision closure. Histological examination HDF cell line demonstrates epithelialization, collagen production, fibroblast migration, polymorphonuclear leukocyte migration (PNML), and fibroblast movement. The results of molecular docking indicate a substantial attraction and contact between MMPs. pkCMS prediction indicates inadequate blood-brain barrier permeability, low toxicity, and absence of hepatotoxicity. 4. Wound healing properties of (NEO) naringin, eicosane and octacosane may be the result of their antioxidant properties and possible interactions with MMP.

The use of babosa (Aloe vera) in treating burns: a literature review.

Alo vera is a centenary remedy use for minor wounds and burns, but its mechanism of wound healing has not been know since. This article will evaluate and gather evidence of the effectiveness and safety of the use of aloe vera in the treatment of burns. A systematic review was carried out on the databases: MEDLINE, LILACS, DECS, SCIELO, in the last 7 years, with the descriptors: "Aloe", "Burns" and "treatment". 16 articles were found. After using the exclusion criteria; research in non-humans and literature review; 5 articles were selected. The article Teplick et al. (2018) performed an in vitro clinical experiment in A. Vera solution, and demonstrated that there was proliferation and cell migration of human skin fibroblasts and keratinocytes, in addition to being protective in the death of keratonocytes. That is, it accelerates the healing of wounds. Muangman et al. (2016), evaluated 50 patients with 20% of the total body surface area burned with second-degree burns, between 18-60 years old, with half of the group receiving gauze dressings with soft paraffin containing 0.5% chlorhexidine acetate and the other half receiving polyester dressings containing extracts of medicinal plants mainly Aloe Vera. It had positive results, a higher healing speed and shorter hospital stay compared to the control group. Hwang et al. (2015) investigated the antioxidant effects of different extracts from 2,4,6,8,12 months of Aloe Vera. And the 6-month concentrated extract of 0.25 mg / mL had a higher content of flavonoids (9.750 mg catechin equivalent / g extract) and polyphenols (23.375 mg gallic acid equivalent / g extract) and the greater ferric reducing antioxidant power (0.047 mM equivalent ferrous sulfate / mg extract), that is, greater potential for free radical scavenging and also a protective effect against oxidative stress induced by tert-butyl hydroperoxide (t-BHP), suggesting evidence of a bioactive potential of A. vera . However, in the article Kolacz et al. (2014) suggested as an alternative treatment the use of Aloe Vera dressing in combination with honey, lanolin, olive oil, wheat germ oil, marshmallow root, wormwood, comfrey root, white oak bark, lobelia inflata, glycerin vegetable oil, beeswax and myrrh, without obtaining significant and conclusive results that would allow the conventional treatment of burns to be subsidized. Finally, in the article by Zurita and Gallegos (2017), it carried out a descriptive cross-sectional study with 321 people, both sexes between 17-76 years of age, of an inductive nature, exploring the experience of this population and their behavioral attitudes regarding the treatment of dermatoses. Aloe vera had 13.8% cited by individuals in the treatment of acne and 33.6% in the treatment of burns. Even with evidence that suggests the efficacy in the treatment of burns with the use of Aloe Vera extract, further clinical trials with larger sample space on the use of Aloe vera dressings in medium burns are suggested for further conclusions.

In vitro and in vivo effect of novel GA-CSNPs loaded col-fibrin nanocomposite scaffold on diabetic wound healing.

A non-healing wound is a common problem associated with diabetes mellitus. Chronic inflammation, challenging re-epithelization, unusual growth factors, and impaired angiogenesis are the multifactorial events that contribute to impaired wounds. Hence, in the present work, an innovative GA-CSNPs nanocomposite scaffold has been fabricated by integrating Gallic acid (GA) loaded chitosan nanoparticles (GA-CSNPs) into a genipin crosslinked collagen-fibrin (Col-fibrin) scaffold as wound dressing material. The in vitro RT-PCR study carried out using NIH/3T3 mouse fibroblast cells showed that treatment with GA-CSNPs nanocomposite scaffold aids in an upsurge in the expression of Col-I, III, and VEGF, which further supports the synthesis of extracellular matrix, increases neovascularization and development of the established vascular system. In vivo wound contraction study results revealed that diabetic wounds treated with GA-CSNPs nanocomposite scaffold show a faster rate of wound closure (p < .001), histopathology results showed accelerated fibroblast cell migration, reduction of the inflammatory cells, enhanced collagen along with hexosamine synthesis. In addition, immunohistochemistry results showed increased vascularization, a significant decrease in macrophage recruitment, and reduced expression of MMP-9 compared to the Col-fibrin scaffold and Control groups. Overall data suggest that the fabricated GA-CSNPs nanocomposite porous 3-D scaffold can be a hopeful therapeutic choice for diabetic wound management.

Bilayer nanofibrous wound dressing prepared by electrospinning containing gallic acid and quercetin with improved biocompatibility, antibacterial, and antioxidant effects

Objecteives The purpose of this study was to prepare an antibacterial, antioxidant, and biocompatible bilayer nanofibrous wound dressing by using electrospinning. Methods The micromorphology and bilayer structure characteristics of the GA-Qe-PVP-PCL nanofibers were analyzed by SEM. The physicochemical characteristics were analyzed by XRD and FTIR. The uptake, mechanical properties, water contact angle, water vapor transmission and in vitro drug release were evaluated. In addition, the effect of antibacterial, antioxidant and biocompatability of the nanofibers were evaluated, respectively. Results The SEM results showed that the GA-Qe-PVP-PCL nanofibers had a smooth surface, no beading phenomenon, and a prominent bilayer structure. The diameter and porosity of the drug-loading layer and waterproof support layer of the nanofibers were 842 ± 302 nm, 242 ± 50 nm, and 88.56 ± 1.67%, 94.49 ± 1.57%, respectively. Moreover, the water uptake, mechanical properties, water contact angle, and water vapor transmission showed ideal performance. The results of in vitro drug release indicated that GA and Qe were both released rapidly, which was conducive to accelerating wound healing. The GA-Qe-PVP-PCL nanofibers exhibited antibacterial effects against both bacteria as well as high antioxidant activity. Additionally, the GA-Qe-PVP-PCL nanofibers possessed good compatibility, could promote the proliferation, adhesion, and migration of L929 fibroblast cells. Conclusion The nanofibers we developed met the requirements of ideal materials for wound dressing, which makes the nanofibers the potential to be a wound dressing for wound care.

Nasal irrigation with licorice extract (Glycyrrhiza glabra) in treating nasal polyps by reducing fibroblast differentiation and extracellular matrix production in TGF-β1-stimulated nasal polyp-derived fibroblasts by inhibiting the MAPK/ERK-1/2 pathway – an in vitro and in clinic study

BackgroundTo date, treating nasal polyps (NPs) is still a medical challenge. However, we have developed an innovative therapy using licorice extract (LE: Glycyrrhiza glabra) to treat rhinitis and sinusitis via nasal irrigation and have discovered that it significantly affects treatment of NPs.Hypothesis/purposeThis study investigated the mechanism of LE on NPs.Study designNPs were collected from three patients using tissue biopsies before and 2 weeks after nasal irrigation with licorice for histopathological analysis. Additionally, NPs from two patients were collected, and nasal polyp-derived fibroblasts (NPDF) were isolated and cultured.MethodsThe TGF-β1-stimulated NPDF model was used to examine the effect of LE on fibroblast differentiation (biomarker: α-SMA), the consequent production of extracellular matrix (ECM; biomarkers: fibronectin, FBN), and the functional signaling pathway.ResultsImmunohistochemistry (IHC) revealed that the number of eosinophils and the expression of α-SMA and interstitial collagen of polyps after licorice treatment significantly decreased. Additionally, RT-PCR, western blotting, and immunofluorescence (IF) showed that α-SMA and FBN expressions were significantly increased in the NPDF, which was stimulated by TGF-β1, and LE dose-dependently could effectively reduce this effect. Furthermore, western blotting showed that LE could attenuate α-SMA and FBN expressions by preventing the signaling pathway of MAPK/ERK-1/2, which IHC and IF further confirmed. In addition, LE effectively suppressed the cell migration of NPDF, which is related to polyp expansion.ConclusionLE is clinically used to treat sinusitis with NPs through nasal irrigation, which significantly reduces the size of NPs. This effect could attenuate fibroblast differentiation, ECM production and cell migration, and one of the functional mechanisms may be through inhibition of the MAPK/ERK-1/2 signaling pathway.Trial registrationISRCTN (No. 51425529) registered on 17/04/2020 (retrospectively registered) - http://www.isrctn.com/ISRCTN51425529

Establishment of fibroblast and myofibroblast phenotypes for use in in vitro co-culture models

Fibroblasts function to secrete and modify components of the extracellular matrix. During wound healing, fibroblasts migrate to the site of injury and differentiate into contractile myofibroblasts; this differentiation is characterised by an increased contractile capacity. Fully differentiated myofibroblasts can be distinguished from fibroblasts via the higher expression of α-smooth muscle actin as well as a denser cytoskeleton. Impaired wound healing has been characterised by a lack of myofibroblasts; as a result, tissue does not fully regain its strength and function. Under pathological conditions, this may be associated with the effect that a pro-inflammatory microenvironment has on fibroblast and skeletal muscle progenitor cell migration and differentiation.Given their distinct roles in tissue maintenance and repair, the communication between fibroblasts versus myofibroblasts with other cellular mediators of repair is likely to influence cell behaviour and the outcome of wound repair. An in vitro test model is required to investigate this intercellular influence, but the establishment of such a model is hampered by the difficulty in retaining the dedifferentiated fibroblastic phenotype under regular serum-containing cell culture conditions. We present a model that supports the establishment and retention in culture of fibroblast and myofibroblast phenotypes for use in a simple, inexpensive, yet relevant in vitro 2D assay. This model is then applied in a co-culture setting to determine whether the presence of myoblasts affects the ability of fibroblasts versus myofibroblasts to close an in vitro wound. Our results emphasize the importance of considering the impact of paracrine communication between all cells during wound healing.

Olive oil promotes the survival and migration of dermal fibroblasts through Nrf2 pathway activation.

Olive oil has beneficial effects on skin wound healing due to its anti-inflammatory and antioxidant properties; however, the mechanism by which olive oil promotes wound healing is unclear. We evaluated the mechanisms involved in Nrf2 pathway activation by olive oil and its role in cell survival and migration in mouse dermal fibroblasts in a short-term exposition. Our data demonstrated that olive oil and oleic acid promoted reactive oxygen species (ROS) production, while olive oil and hydroxytyrosol stimulated nuclear factor erythroid 2-related factor 2 (Nrf2) activation. Olive oil-mediated ROS production increased nuclear factor kappa B p65 expression, while olive oil-stimulated reactive nitrogen species production augmented the levels of Nrf2. Olive oil augmented cell proliferation, cell migration, and AKT phosphorylation, but decreased apoptotic cell number and cleaved caspase-3 levels. The effect of olive oil on cell migration and protein levels of AKT, BCL-2, and Nrf2 were reversed by an Nrf2 inhibitor. In conclusion, the activation of the Nrf2 pathway by olive oil promotes the survival and migration of dermal fibroblasts that are essential for the resolution of skin wound healing.

Hydroxyapatite Modified Silica Aerogel Nanoparticles: In Vitro Cell Migration Analysis

The ability of silica aerogel nanoparticles (SA-Np) to improve the stability of hydroxyapatite (HA) was investigated. Using the sol-gel method, the HA was incorporated into SA-Np at a weight ratio of 0.5 of HA to SiO2 (HA-SA-Np). The efficacy of HA-SA-Np, SA-Np, and HA on the in vitro migration of normal human dermal fibroblast cells (HSF1184) was compared. The cell migration was measured at 0, 6, and 24 hours after scratching using ImageJ and an inverted optical microscope. To ascertain the resorbability of HA-SA-Np, the phosphate and silicic acid concentrations in media treated for 2, 5, and 7 days were examined. The high dissolution of HA could be reduced by incorporating the HA into the silica nanosphere. The HA-SA-Np significantly stimulated cell migration and increased closure with increasing treatment time. It was caused by the release of silicic acid, which aided in healing cells. It also demonstrates the ability of HA-SA-Np to be resorbed and eventually increase the adhesion and migration of normal human fibroblast cells. As a result, the potential application of HA-SA-Np as an alternative biomaterial was confirmed.

Electrostimulation of fibroblast proliferation by an electrospun poly (lactide-co-glycolide)/polydopamine/chitosan membrane in a humid environment

Exogenous electrical stimulation (ES) facilitates skin wound healing and accelerates cell proliferation. Scaffolds fabricated with electrically-conductive materials combined with ES further promote cellular activity. Here, an electrospun membrane made of poly (lactide-co-glycolide) (PLGA) coated with chitosan (CS) via polydopamine (PDA) serving as a linker was developed and evaluated in vitro for the proliferation and migration of fibroblast cells involved in skin wound repair. PLGA/PDA/CS exhibited multiple optimal characteristics for cell proliferation and dressing materials including good mechanical properties, low cytotoxicity, a super-hydrophilic surface, and an excellent swelling ratio suitable for the absorption of wound exudates. Because of ionic charges, wet PLGA/PDA/CS had an electrical conductivity of 2.85 × 10-3 S/cm, which was comparable to the highest electrical conductivities observed with natural skin. Upon intermittent ES of 100 mV, PLGA/PDA/CS increased fibroblast proliferation 2 and 1.3 times compared to PLGA and PLGA/PDA, respectively. These results demonstrate the potential of PLGA/PDA/CS as a biodegradable polymeric surface for the ES of cells involved in skin wound healing. It also shows that polymers with low electrical conductivity in dry conditions can become suitable for the ES of humid wounds where ionic conductivity is occurring.

WNT1 Inducible Signaling Pathway Protein 1 Is a Stroma-Specific Secreting Protein Inducing a Fibroblast Contraction and Carcinoma Cell Growth in the Human Prostate.

The WNT1 inducible signaling pathway protein 1 (WISP1), a member of the connective tissue growth factor family, plays a crucial role in several important cellular functions in a highly tissue-specific manner. Results of a RT-qPCR indicated that WISP1 expressed only in cells of the human prostate fibroblasts, HPrF and WPMY-1, but not the prostate carcinoma cells in vitro. Two major isoforms (WISP1v1 and WISP1v2) were identified in the HPrF cells determined by RT-PCR and immunoblot assays. The knock-down of a WISP1 blocked cell proliferation and contraction, while treating respectively with the conditioned medium from the ectopic WISP1v1- and WISPv2-overexpressed 293T cells enhanced the migration of HPrF cells. The TNFα induced WISP1 secretion and cell contraction while the knock-down of WISP1 attenuated these effects, although TNFα did not affect the proliferation of the HPrF cells. The ectopic overexpression of WISP1v1 but not WISP1v2 downregulated the N-myc downstream regulated 1 (NDRG1) while upregulating N-cadherin, slug, snail, and vimentin gene expressions which induced not only the cell proliferation and invasion in vitro but also tumor growth of prostate carcinoma cells in vivo. The results confirmed that WISP1 is a stroma-specific secreting protein, enhancing the cell migration and contraction of prostate fibroblasts, as well as the proliferation, invasion, and tumor growth of prostate carcinoma cells.

Design and Investigation of an Eco-Friendly Wound Dressing Composed of Green Bioresources- Soy Protein, Tapioca Starch, and Gellan Gum.

In the fields of biomedicine and tissue engineering, natural polymer-based tissue-engineered scaffolds are used in multiple applications. As a plant-derived polymer, soy protein, containing multiple amino acids, is structurally similar to components of the extra-cellular matrix (ECM) of tissues. It is biological safety provided a good potential to be material for pure natural scaffolds. Moreover, as a protein, the properties of soy protein can be easily adjusted by modifying the functional groups on it. In addition, by blending soy protein with other synthetic and natural polymers, the mechanical characteristics and bioactive behavior of scaffolds can be facilitated for a variety of bio-applications. In this research, soy protein and polysaccharides tapioca starch are used, and gellan gum to develop a protein-based composite scaffold for cell engineering. The morphology and surface chemical composition are characterized via micro-computed tomography (micro-CT), scanning electron microscope (SEM), and fourier-transform infrared (FTIR) spectroscopy. The soy/tapioca/gellan gum (STG) composite scaffolds selectively help the adhesion and proliferation of L929 fibroblast cells while improving the migration of L929 fibroblast cells in STG composite scaffolds as the increase of soy protein proportion of the scaffold. In addition, STG composite scaffolds show great potential in the wound healing model to enhance rapid epithelialization and tissue granulation.

An automated high-throughput platform for experimental study of burn injuries - in vitro and ex vivo

The use of in-vitro and ex-vivo models for the study of burn wound injuries is encouraged to reduce the animal burden in experimental burn research. However, few existing platforms enable the production of reproducible, locally confined thermal injuries at short durations in a high-throughput manner for both in-vitro and ex-vivo models. To address this gap, we established an automated high-throughput burn platform (HTBP) that provided accurate control over burn temperature, exposure time, and pressure application. This platform was built by fabricating an aluminum heat block with 96 pins and positioning a high-resolution actuator below the block. By activating the actuator, 96-well cell culture plates and skin samples were pressed against the heat block’s pins. We demonstrated the applicability of the HTBP for studying in-vitro burn injuries by investigating the effects of burn temperature and contact duration on cell viability and migration in human umbilical vein endothelial cells and NIH-3T3 fibroblasts. We showed that higher temperatures and a longer contact duration decreased cellular viability and increased the area of the burn. Moreover, we found that even a short exposure time of 200 msec caused a severe burn wound at 75 °C in a cell monolayer. In addition, we used the HTBP to generate burn injuries at different burn durations in ex-vivo porcine skin and showed that dermis discoloration was present in histologic sections after exposure to 100 °C for a short duration of 500 msec. Our work demonstrates that the HTBP can constitute an important tool for both in-vitro and ex-vivo research of mild and severe burn injuries in a tightly controlled setting and high-throughput manner.

Photobiomodulation at 830 nm Stimulates Migration, Survival and Proliferation of Fibroblast Cells.

PurposePhotobiomodulation (PBM) promotes diabetic wound healing by favoring cell survival and proliferation. This study aimed to investigate the potential of PBM in stimulating cellular migration, viability, and proliferation using the transforming growth factor-β1 (TGF-β1)/Smad signaling pathway.MethodsThe study explored the in vitro effects of near infrared (NIR) light on cell viability (survival) and proliferation as well as the presence of TGF-β1, phosphorylated TGF‐β receptor type I (pTGF-βR1) and phosphorylated mothers against decapentaplegic‐homolog (Smad)‐2/3 (p-Smad2/3) in different fibroblast cell models.ResultsResults show a significant increase in cellular migration in wounded models, and increased viability and proliferation in irradiated cells compared to their respective controls. An increase in the presence of TGF-β1 in the culture media, a reduction in pTGF-βR1 and a slight presence of p-Smad2/3 was observed in the cells.ConclusionThese findings show that PBM at 830 nm using a fluence of 5 J/cm2 could induce cell viability, migration and proliferation to favor successful healing of diabetic wounds. This study contributes to the growing body of knowledge on the molecular and cellular effect of PBM and showcases the suitability of PBM at 830 nm in managing diabetic wounds.

Molecular basis of clot retraction and its role in wound healing

Clot retraction is important for the prevention of bleeding, in the manifestations of thrombosis and for tissue repair. The molecular mechanisms behind clot formation are complex. Platelet involvement begins with adhesion at sites of vessel injury followed by platelet aggregation, thrombin generation and fibrin production. Other blood cells incorporate into a fibrin mesh that is consolidated by FXIIIa-mediated crosslinking and platelet contractile activity. The latter results in the asymmetric redistribution of erythrocytes into a tighter central mass providing the clot with stability and resistance to fibrinolysis. Integrin αIIbβ3 on platelets is the key player in these events, bridging fibrin and the platelet cytoskeleton. Glycoprotein VI participates in thrombus formation but not in the retraction. Rheological and environmental factors influence clot construction with retraction driven by the platelet cytoskeleton with actomyosin acting as the motor. Activated platelets provide procoagulant activity stimulating thrombin generation together with the release of a plethora of biologically active proteins and substances from storage pools; many form chemotactic gradients within the fibrin or the underlying matrix. Also released are newly synthesized metabolites and lipid-rich vesicles that circulate within the vasculature and mimic platelet functions. Platelets and their released elements play key roles in wound healing. This includes promoting stem cell and mesenchymal stromal cell recruitment, fibroblast and endothelial cell migration, angiogenesis and matrix formation. These properties have led to the use of autologous clots in therapies designed to accelerate tissue repair while offering the potential for genetic manipulation in both inherited and acquired diseases.

Antioxidant Silk Fibroin Composite Hydrogel for Rapid Healing of Diabetic Wound.

Wound healing is a complex process requiring multiple biological pathways and chemical responses to be activated and synchronized to recover tissue integrity. In normal physiological circumstances, the epidermal barrier restoration process through new tissue formation is highly efficient. However, increased production of reactive oxygen species (ROS), attack of pathogenic microorganisms, and high glucose level delay the normal healing process in diabetic patients. The successful treatment of diabetic wounds requires efficient strategies to control oxidative stress, promoting angiogenesis, re-epithelialization, and collagen deposition. In this study, a composite hydrogel for rapid wound healing in diabetic condition is developed by the amalgamation of hypolipidemic property of silk fibroin (SF), antioxidant property of melanin, and therapeutic effect of berberine. Studies have revealed that cross-linked mesoporous morphology of hydrogel matrix facilitates slow release of berberine to impart long-term therapeutic effects at wound site. The composite hydrogel formulation is biocompatible, stimulates effective migration of fibroblast cells, and control oxidative stress under in vitro conditions. The hydrogel served as scaffold for tissue re-epithelialization and promotes wound repair in diabetic type I Wistar rat model. This study demonstrates the ability of berberine- loaded SF-melanin composite hydrogel as a potential dressing formulation for wound healing in diabetic conditions.

Human iPSC-Vascular smooth muscle cell spheroids demonstrate size-dependent alterations in cellular viability and secretory function.

Human-induced pluripotent stem cells (hiPSC) and their differentiated vascular cells have been revolutionizing the field of regenerative wound healing. These cells are shown to be rejuvenated with immense potentials in secreting paracrine factors. Recently, hiPSC-derived vascular smooth muscle cells (hiPSC-VSMC) have shown regenerative wound healing ability via their paracrine secretion. The quest to modulate the secretory function of these hiPSC-VSMC is an ongoing effort and involves the use of both biochemical and biophysical stimuli. This study explores the development and optimization of a reproducible, inexpensive protocol to form hiPSC-VSMC derived spheroids to investigate the implications of spheroid size on viability and paracrine secretion. Our data show the successful formation of different sizes of spheroids using various amount of hiPSC-VSMC. The hiPSC-VSMC spheroids formed with 10,000 cells strike an ideal balance between overall cell health and maximal paracrine secretion. The conditioned medium from these spheroids was found to be bioactive in enhancing human dermal fibroblast cell proliferation and migration. This research will inform future studies on the optimal spheroid size for regenerative wound healing applications.

Exosomes Derived From Umbilical Cord Mesenchymal Stem Cells Treat Cutaneous Nerve Damage and Promote Wound Healing.

Wound repair is a key step in the treatment of skin injury caused by burn, surgery, and trauma. Various stem cells have been proven to promote wound healing and skin regeneration as candidate seed cells. Therefore, exosomes derived from stem cells are emerging as a promising method for wound repair. However, the mechanism by which exosomes promote wound repair is still unclear. In this study, we reported that exosomes derived from umbilical cord mesenchymal stem cells (UC-MSCs) promote wound healing and skin regeneration by treating cutaneous nerve damage. The results revealed that UC-MSCs exosomes (UC-MSC-Exo) promote the growth and migration of dermal fibroblast cells. In in vitro culture, dermal fibroblasts could promote to nerve cells and secrete nerve growth factors when stimulated by exosomes. During the repair process UC-MSC-Exo accelerated the recruitment of fibroblasts at the site of trauma and significantly enhanced cutaneous nerve regeneration in vivo. Interestingly, it was found that UC-MSC-Exo could promote wound healing and skin regeneration by recruiting fibroblasts, stimulating them to secrete nerve growth factors (NGFs) and promoting skin nerve regeneration. Therefore, we concluded that UC-MSC-Exo promote cutaneous nerve repair, which may play an important role in wound repair and skin regeneration.

Abstract 2406: Mechanism of mSin1 regulation of cell migration

Abstract Studies have shown that mSin1, a major component of mTORC2, plays an important role in tumor cell migration and invasion as well as cancer metastasis. However, how mSin1 regulates cell migration is poorly understood. In this study, we found that knockout of mSin1 suppressed cell spreading and migration in mouse embryo fibroblasts (MEFs). Similarly, knockdown of mSin1 also inhibited cell spreading and migration in rhabdomyosarcoma (Rh30) and cervical cancer (HeLa) cells. Furthermore, we observed that knockout or knockdown of mSin1 reduced the activities of the small GTPases (RhoA and Rac1) in the cells. Ectopic expression of constitutively active Rac1, but not RhoA, partially attenuated the reduced cell spreading and migration induced by mSin1 deficiency. In addition, depletion of mSin1 remarkedly inhibited the phosphorylation of focal adhesion proteins, including focal adhesion kinase (FAK) at Tyr397 and paxillin at Tyr118 in the cells. The results suggest that mSin1 controls cell spreading and migration at least partly by mediating the activity of Rac1 and the phosphorylation of FAK. (Supported by the Feist-Weiller Cancer Center, LSU Health Sciences Center, Shreveport, LA, USA) Citation Format: Shile Huang, Lei Liu, Yan Luo. Mechanism of mSin1 regulation of cell migration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2406.