scholarly journals Plasma-polymerized pericyte patches improve healing of murine wounds through increased angiogenesis and reduced inflammation

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Hannah M Thomas ◽  
Parinaz Ahangar ◽  
Robert Fitridge ◽  
Giles T S Kirby ◽  
Stuart J Mills ◽  
...  

Abstract Pericytes have the potential to be developed as a cell therapy for the treatment of wounds; however, the efficacy of any cell therapy relies on the successful delivery of intact and functioning cells. Here, the effect of delivering pericytes on wound repair was assessed alongside the development of a surface-functionalized pericyte patch. Plasma polymerization (PP) was used to functionalize the surface of silicone patches with heptylamine (HA) or acrylic acid (AA) monomers. Human pericytes were subsequently delivered to murine excisional wounds by intradermal injection or using the pericyte-laden patches and the comparative effects on wound healing, inflammation and revascularization determined. The AA surface provided the superior transfer of the cells to de-epidermized dermis. Excisional murine wounds treated either with pericytes injected directly into the wound or with the pericyte-laden AA patches showed improved healing with decreased neutrophil infiltration and reduced numbers of macrophages in the wounds. Pericyte delivery also enhanced angiogenesis through a mechanism independent of VEGF signalling. Pericytes, when delivered to wounds, improved healing responses by dampening inflammation and promoting angiogenesis. Delivery of pericytes using PP-AA-functionalized patches was equally as effective as direct injection of pericytes into wounds. Pericyte-functionalized dressings may therefore be a clinically relevant approach for the treatment of wounds.

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2635
Author(s):  
Caroline Tyavambiza ◽  
Phumuzile Dube ◽  
Mediline Goboza ◽  
Samantha Meyer ◽  
Abram Madimabe Madiehe ◽  
...  

In Africa, medicinal plants have been traditionally used as a source of medicine for centuries. To date, African medicinal plants continue to play a significant role in the treatment of wounds. Chronic wounds are associated with severe healthcare and socio-economic burdens despite the use of conventional therapies. Emergence of novel wound healing strategies using medicinal plants in conjunction with nanotechnology has the potential to develop efficacious wound healing therapeutics with enhanced wound repair mechanisms. This review identified African medicinal plants and biogenic nanoparticles used to promote wound healing through various mechanisms including improved wound contraction and epithelialization as well as antibacterial, antioxidant and anti-inflammatory activities. To achieve this, electronic databases such as PubMed, Scifinder® and Google Scholar were used to search for medicinal plants used by the African populace that were scientifically evaluated for their wound healing activities in both in vitro and in vivo models from 2004 to 2021. Additionally, data on the wound healing mechanisms of biogenic nanoparticles synthesized using African medicinal plants is included herein. The continued scientific evaluation of wound healing African medicinal plants and the development of novel nanomaterials using these plants is imperative in a bid to alleviate the detrimental effects of chronic wounds.


Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1544 ◽  
Author(s):  
Simona Martinotti ◽  
Giorgia Pellavio ◽  
Umberto Laforenza ◽  
Elia Ranzato

Propolis is the generic name of a complex of resinous compound collected by honeybees and it has been utilized for many years in folk medicine. As other products generated by honeybees (such as royal jelly, pollen, honey), propolis has great therapeutic properties, but very little scientific information is available. Therefore, this study was aimed at exploring the potential wound healing properties of propolis. To that end, we utilized an in vitro scratch wound healing model consisting of human immortalized keratinocytes. Our scratch wound data clearly demonstrated that propolis induced a pronounced increase in the wound repair abilities of keratinocytes. A cell migration assay showed that propolis stimulated keratinocytes to close the wound. We revealed the role of H2O2 as the main mediator of propolis regenerative properties. We showed that this extracellularly released H2O2 could pass across the plasma membrane through a specific aquaporin (i.e., AQP3) modulating intracellular responses. The data offer a biological characterization of propolis positive effects suggesting that propolis could also be utilized in wound treatment within clinical settings.


Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2830
Author(s):  
Mengting Qi ◽  
Xuerui Zhu ◽  
Xiaoyi Yu ◽  
Min Ai ◽  
Weiwei Cai ◽  
...  

Chronic wound repair is a common complication in patients with diabetes mellitus, which causes a heavy burden on social medical resources and the economy. Hypaphorine (HYP) has good anti-inflammatory effect, and chitosan (CS) is used in the treatment of wounds because of its good antibacterial effect. The purpose of this research was to investigate the role and mechanism of HYP-nano-microspheres in the treatment of wounds for diabetic rats. The morphology of HYP-NPS was observed by transmission electron microscopy (TEM). RAW 264.7 macrophages were used to assess the bio-compatibility of HYP-NPS. A full-thickness dermal wound in a diabetic rat model was performed to evaluate the wound healing function of HYP-NPS. The results revealed that HYP-NPS nanoparticles were spherical with an average diameter of approximately 50 nm. The cell experiments hinted that HYP-NPS had the potential as a trauma material. The wound test in diabetic rats indicated that HYP-NPS fostered the healing of chronic wounds. The mechanism was through down-regulating the expression of pro-inflammatory cytokines IL-1β and TNF-α in the skin of the wound, and accelerating the transition of chronic wound from inflammation to tissue regeneration. These results indicate that HYP-NPS has a good application prospect in the treatment of chronic wounds.


2015 ◽  
Vol 309 (5) ◽  
pp. H812-H826 ◽  
Author(s):  
Mateusz S. Wietecha ◽  
Mateusz J. Król ◽  
Elizabeth R. Michalczyk ◽  
Lin Chen ◽  
Peter G. Gettins ◽  
...  

During dermal wound repair, hypoxia-driven proliferation results in dense but highly permeable, disorganized microvascular networks, similar to those in solid tumors. Concurrently, activated dermal fibroblasts generate an angiopermissive, provisional extracellular matrix (ECM). Unlike cancers, wounds naturally resolve via blood vessel regression and ECM maturation, which are essential for reestablishing tissue homeostasis. Mechanisms guiding wound resolution are poorly understood; one candidate regulator is pigment epithelium-derived factor (PEDF), a secreted glycoprotein. PEDF is a potent antiangiogenic in models of pathological angiogenesis and a promising cancer and cardiovascular disease therapeutic, but little is known about its physiological function. To examine the roles of PEDF in physiological wound repair, we used a reproducible model of excisional skin wound healing in BALB/c mice. We show that PEDF is abundant in unwounded and healing skin, is produced primarily by dermal fibroblasts, binds to resident microvascular endothelial cells, and accumulates in dermal ECM and epidermis. PEDF transcript and protein levels were low during the inflammatory and proliferative phases of healing but increased in quantity and colocalization with microvasculature during wound resolution. Local antibody inhibition of endogenous PEDF delayed vessel regression and collagen maturation during the remodeling phase. Treatment of wounds with intradermal injections of exogenous, recombinant PEDF inhibited nascent angiogenesis by repressing endothelial proliferation, promoted vascular integrity and function, and increased collagen maturity. These results demonstrate that PEDF contributes to the resolution of healing wounds by causing regression of immature blood vessels and stimulating maturation of the vascular microenvironment, thus promoting a return to tissue homeostasis after injury.


Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.


Cytotherapy ◽  
2016 ◽  
Vol 18 (9) ◽  
pp. 1087-1099 ◽  
Author(s):  
Gabriela Ciapetti ◽  
Donatella Granchi ◽  
Caterina Fotia ◽  
Lucia Savarino ◽  
Dante Dallari ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jian Zhang ◽  
Yongjun Zheng ◽  
Jimmy Lee ◽  
Jieyu Hua ◽  
Shilong Li ◽  
...  

AbstractEffective healing of skin wounds is essential for our survival. Although skin has strong regenerative potential, dysfunctional and disfiguring scars can result from aberrant wound repair. Skin scarring involves excessive deposition and misalignment of ECM (extracellular matrix), increased cellularity, and chronic inflammation. Transforming growth factor-β (TGFβ) signaling exerts pleiotropic effects on wound healing by regulating cell proliferation, migration, ECM production, and the immune response. Although blocking TGFβ signaling can reduce tissue fibrosis and scarring, systemic inhibition of TGFβ can lead to significant side effects and inhibit wound re-epithelization. In this study, we develop a wound dressing material based on an integrated photo-crosslinking strategy and a microcapsule platform with pulsatile release of TGF-β inhibitor to achieve spatiotemporal specificity for skin wounds. The material enhances skin wound closure while effectively suppressing scar formation in murine skin wounds and large animal preclinical models. Our study presents a strategy for scarless wound repair.


2007 ◽  
Vol 22 (2) ◽  
pp. 49-55 ◽  
Author(s):  
R Ogrin ◽  
P Darzins ◽  
Z Khalil

Objectives: Venous leg ulcers represent a major clinical problem, with poor rates of healing. Ideal treatment is compression bandaging. The effect of compression on neurovascular tissues involved in wound repair is unclear. This study aims to assess the effect of four-layer compression therapy (40 mmHg) on neurovascular function and wound healing in people with chronic venous leg ulcers – 15 people (55 years or older) with venous leg ulcers for more than six weeks. Methods: Basal microvascular perfusion measurement (MPM), oxygen tension (tc pO2) measured at sensor temperatures of 39°C and 44°C and sensory nerve function using electrical cutaneous perception thresholds (ECPT) at 5, 250 and 2000 Hz (corresponding to C, A δ and A β fibres) were assessed adjacent to the ulcer site, and at a mirror location on the non-ulcerated limb. Testing was undertaken before and after therapy for 5–12 weeks of four-layer compression bandaging. Results: There was significant improvement in tc pO2 at 44°C and ECPT at 2000 Hz ( P<0.05) compared with pre-intervention. Changes in basal MPM, tc pO2 at 39°C and ECPT at 5 and 250 Hz after compression therapy did not reach statistical significance. Conclusion: Four-layer compression bandaging in people with venous leg ulcers improved some components of neurovascularture in people with chronic venous leg ulcers. Whether this improvement has contributed to wound healing in this study requires further investigation.


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