scholarly journals Eradication of Mature Bacterial Biofilms with Concurrent Improvement in Chronic Wound Healing Using Silver Nanoparticle Hydrogel Treatment

Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1182
Author(s):  
Hanif Haidari ◽  
Richard Bright ◽  
Sanjay Garg ◽  
Krasimir Vasilev ◽  
Allison J. Cowin ◽  
...  

Biofilm-associated infections are a major cause of impaired wound healing. Despite the broad spectrum of anti-bacterial benefits provided by silver nanoparticles (AgNPs), these materials still cause controversy due to cytotoxicity and a lack of efficacy against mature biofilms. Herein, highly potent ultrasmall AgNPs were combined with a biocompatible hydrogel with integrated synergistic functionalities to facilitate elimination of clinically relevant mature biofilms in-vivo combined with improved wound healing capacity. The delivery platform showed a superior release mechanism, reflected by high biocompatibility, hemocompatibility, and extended antibacterial efficacy. In vivo studies using the S. aureus wound biofilm model showed that the AgNP hydrogel (200 µg/g) was highly effective in eliminating biofilm infection and promoting wound repair compared to the controls, including silver sulfadiazine (Ag SD). Treatment of infected wounds with the AgNP hydrogel resulted in faster wound closure (46% closure compared to 20% for Ag SD) and accelerated wound re-epithelization (60% for AgNP), as well as improved early collagen deposition. The AgNP hydrogel did not show any toxicity to tissue and/or organs. These findings suggest that the developed AgNP hydrogel has the potential to be a safe wound treatment capable of eliminating infection and providing a safe yet effective strategy for the treatment of infected wounds.

1999 ◽  
Vol 277 (4) ◽  
pp. H1600-H1608 ◽  
Author(s):  
Paul C. Lee ◽  
A. Neil Salyapongse ◽  
Gwynne A. Bragdon ◽  
Larry L. Shears ◽  
Simon C. Watkins ◽  
...  

A role for nitric oxide (NO) in wound healing has been proposed; however, the absolute requirement of NO for wound healing in vivo and the contribution of endothelial NO synthase (eNOS) have not been determined. Experiments were carried out using eNOS gene knockout (KO) mice to determine the requirement for eNOS on wound closure and wound strength. Excisional wound closure was significantly delayed in the eNOS KO mice (29.4 ± 2.2 days) compared with wild-type (WT) controls (20.2 ± 0.4 days). At 10 days, incisional wound tensile strength demonstrated a 38% reduction in the eNOS KO mice. Because effective wound repair requires growth factor-stimulated angiogenesis, in vitro and in vivo angiogenesis assays were performed in the mice to assess the effects of eNOS deficiency on angiogenesis. Endothelial cell sprouting assays confirmed in vitro that eNOS is required for proper endothelial cell migration, proliferation, and differentiation. Aortic segments harvested from eNOS KO mice cultured with Matrigel demonstrated a significant reduction in endothelial cell sprouting and [3H]thymidine incorporation compared with WT mice at 5 days. Capillary ingrowth into subcutaneously implanted Matrigel plugs was significantly reduced in eNOS KO mice (2.67 ± 0.33 vessels/plug) compared with WT mice (10.17 ± 0.79 vessels/plug). These results clearly show that eNOS plays a significant role in facilitating wound repair and growth factor-stimulated angiogenesis.


2008 ◽  
Vol 20 (9) ◽  
pp. 22
Author(s):  
T. J. Kaitu'u-Lino ◽  
D. J. Phillips ◽  
N. B. Morison ◽  
L. A. Salamonsen

10% of Australian women suffer from abnormal uterine bleeding (AUB). To stop endometrial bleeding after menstruation, the endometrium must repair adequately. We propose that endometrial restoration after menstruation has characteristics of wound healing and that inadequate endometrial repair may result in AUB. In vivo studies support a contribution of activins to skin wound healing: in mice overexpressing activins' natural inhibitor, follistatin, wound healing is significantly delayed (1). We hypothesised that activin would enhance endometrial repair and examined its contribution using an in vitro wound healing model and our well characterised in vivo mouse model of endometrial breakdown and repair (2). For the in vitro model, confluent human endometrial epithelial cells (ECC-1 cell line) were wounded and treated with carrier protein (control, 0.1% BSA), activin A (50ng/mL) or EGF (positive control: 50ng/mL). Wound areas were quantitated daily for 6 days. For the in vivo study, serum follistatin levels were measured by ELISA in follistatin overexpressing mice (FS) (2) and wild-type (WT) littermates. Mice were induced to undergo endometrial breakdown and repair (mimicking menstruation in women). Activin βA was immunolocalised during endometrial repair, and extent of repair assessed using our morphological scoring system (2). ECC-1 wound repair was significantly (P < 0.05) enhanced by activin A treatment v. control from days 2–6 of culture. In WT mice, activin βA localised to areas of endometrial repair. Serum follistatin was significantly elevated in FS mice v. controls (33.3 ± 3.8 v 7.07 ± 1.8 ng/mL, P < 0.01). In FS mice (n = 8) only 50% of uterine sections showed complete repair after endometrial breakdown, significantly less than those from WT animals (n = 15, P < 0.05) where 85% of sections demonstrated complete repair. These results demonstrate for the first time that activin A functions to promote endometrial restoration following menses and that this can be delayed under physiological conditions: such studies indicate potential treatments for AUB. (1) Wankell et al. (2001) EMBO J 20:5361–5372 (2) Kaitu'u-Lino et al. (2007) Endocrinology 148:5105–5111


2019 ◽  
Vol 5 (7) ◽  
pp. eaaw3963 ◽  
Author(s):  
S. O. Blacklow ◽  
J. Li ◽  
B. R. Freedman ◽  
M. Zeidi ◽  
C. Chen ◽  
...  

Inspired by embryonic wound closure, we present mechanically active dressings to accelerate wound healing. Conventional dressings passively aid healing by maintaining moisture at wound sites. Recent developments have focused on drug and cell delivery to drive a healing process, but these methods are often complicated by drug side effects, sophisticated fabrication, and high cost. Here, we present novel active adhesive dressings consisting of thermoresponsive tough adhesive hydrogels that combine high stretchability, toughness, tissue adhesion, and antimicrobial function. They adhere strongly to the skin and actively contract wounds, in response to exposure to the skin temperature. In vitro and in vivo studies demonstrate their efficacy in accelerating and supporting skin wound healing. Finite element models validate and refine the wound contraction process enabled by these active adhesive dressings. This mechanobiological approach opens new avenues for wound management and may find broad utility in applications ranging from regenerative medicine to soft robotics.


2018 ◽  
Vol 33 (4) ◽  
pp. 527-540 ◽  
Author(s):  
Marek Konop ◽  
Joanna Czuwara ◽  
Ewa Kłodzińska ◽  
Anna K Laskowska ◽  
Urszula Zielenkiewicz ◽  
...  

Impaired wound healing is a major medical problem in diabetes. The objective of this study was to determine the possible application of an insoluble fraction of fur-derived keratin biomaterial as a wound dressing in a full thickness surgical skin wound model in mice ( n = 20) with iatrogenically induced diabetes. The obtained keratin dressing was examined in vitro and in vivo. In vitro study showed the keratin dressing is tissue biocompatible and non-toxic for murine fibroblasts. Antimicrobial examination revealed the keratin dressing inhibited the growth of S. aureus and E. coli. In vivo studies showed the obtained dressing significantly ( p < 0.05) accelerated healing during the first week after surgery compared to control wounds. Keratin dressings were incorporated naturally into granulation and regenerating tissue without any visible signs of inflammatory response, which was confirmed by clinical and histopathological analysis. It is one of the first studies to show application of insoluble keratin proteins and its properties as a wound dressing. The obtained keratin dressing accelerated wound healing in mice with iatrogenically induced diabetes. Therefore, it can be considered as a safe and efficient wound dressing. Although future studies are needed to explain the molecular mechanism behind fur-derived keratin effect during the multilayer wound healing process, our findings may open the way for a new class of insoluble fur keratin dressings in chronic difficult to heal wounds treatment.


2020 ◽  
Vol 16 (8) ◽  
pp. 1229-1240
Author(s):  
Dongping Zhang ◽  
Qiang Huang

Impaired wound healing that occurs in diabetics can result in many life-threatening complications associated with excessive expression of matrix metalloproteinases (MMPs), which mediate the proteolysis of major matrix constituents. In this study, the dendrimer polyamidoamine (PAMAM) and the polysaccharide hyaluronic acid (HA) were connected through the substrate polypeptide (Gly-PLGLAG-Cys) of MMP-2 to obtain the MMP-2-responsive nanocarrier HA-pep-PAMAM. Insoluble astragaloside (ASI) was encapsulated in this nanocarrier to achieve controlled release at the site of intractable wounds. The HA-pep-PAMAM-ASI was successfully prepared with an average diameter of 142.3 ± 28.9 nm. Immunohistochemical staining of the skin revealed that the hard-to-heal wounds of diabetic mice showed stronger expression of MMP-2 than the wounds of normal mice. HA-pep-PAMAM-ASI achieved 73.9% release in the presence of MMP-2, but only 13.5% in PBS. A dose-dependent effect of H2O2 on the proliferation of BJ and HaCaT cells was observed, and HA-pep-PAMAM-ASI treatment had the best antioxidant capacity with MMP-2 pretreatment. HA-pep-PAMAM-ASI significantly increased GSH levels and reduced reactive oxygen species (ROS) levels to achieve antioxidant effects. The MMP-2-pretreated HA-pep-PAMAM-ASI group showed more improved cell proliferation and migration abilities. Compared with ASI group, the expression of all wound-repair-related genes in the group of HA-pep-PAMAM-ASI was significantly increased, and HA-pep-PAMAM-ASI showed a pronounced in vivo therapeutic effect. Therefore, our results revealed that enzyme-responsive MMP-2-loaded PAMAM nanoparticles could promote wound healing in diabetes and may be a promising biomaterial for treatment.


2020 ◽  
Vol 21 (11) ◽  
pp. 4176 ◽  
Author(s):  
Tomohiro Takayama ◽  
Masayuki Ishihara ◽  
Shingo Nakamura ◽  
Yoko Sato ◽  
Sumiyo Hiruma ◽  
...  

Bioshell calcium oxide (BiSCaO) possesses deodorizing properties and broad microbicidal activity. This study aimed to investigate the application of BiSCaO ointment for the prevention and treatment of infection in chronic wounds in healing-impaired patients, without delaying wound healing. The bactericidal activities of 0.04, 0.2, 1, and 5 wt% BiSCaO ointment, 3 wt% povidone iodine ointment, and control (ointment only) were compared to evaluate the in vivo disinfection and healing of Pseudomonas aeruginosa-infected wounds in hairless rats. Treatment of the infected wounds with 0.2 wt% BiSCaO ointment daily for 3 days significantly enhanced wound healing and reduced the in vivo bacterial counts compared with povidone iodine ointment and control (no wound cleaning). Although 5 wt% BiSCaO ointment provided the lowest bacterial counts during 3 days’ treatment, it delayed wound healing. Histological examinations showed significantly advanced granulation tissue and capillary formation in wounds treated with 0.2 wt% BiSCaO ointment for 3 days compared to wounds treated with the other ointments. This study suggested that using 0.2 wt% BiSCaO ointment as a disinfectant for infected wounds and limiting disinfection to 3 days may be sufficient to avoid the negative effects of BiSCaO on wound repair.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3790
Author(s):  
Yt Jun Cheah ◽  
Muhamad Ramdzan Buyong ◽  
Mohd Heikal Mohd Mohd Yunus

Electrical stimulation (ES) is an attractive field among clinicians in the topic of wound healing, which is common yet complicated and requires multidisciplinary approaches. The conventional dressing and skin graft showed no promise on complete wound closure. These urge the need for the exploration of electrical stimulation to supplement current wound care management. This review aims to provide an overview of electrical stimulation in wound healing. The mechanism of galvanotaxis related to wound repair will be reviewed at the cellular and molecular levels. Meanwhile, different modalities of externally applied electricity mimicking a physiologic electric field will be discussed and compared in vitro, in vivo, and clinically. With the emerging of tissue engineering and regenerative medicine, the integration of electroconductive biomaterials into modern miniaturised dressing is of interest and has become possible with the advancing understanding of smart biomaterials.


Author(s):  
Bhikshapathi D. V. R. N. ◽  
Kanteepan P

Rebamipide, an amino acid derivative of 2-(1H)-quinolinone, is used for mucosal protection, healing of gastroduodenal ulcers, and treatment of gastritis. The current research study aimed to develop novel gastro-retentive mucoadhesive microspheres of rebamipide using ionotropic gelation technique. Studies of micromeritic properties confirmed that microspheres were free flowing with good packability. The in vitro drug release showed the sustained release of rebamipide up to 99.23 ± 0.13% within 12 h whereas marketed product displayed the drug release of 95.15 ± 0.23% within 1 h. The release mechanism from microspheres followed the zero-order and Korsmeyer-Peppas (R2 = 0.915, 0.969), respectively. The optimized M12 formulation displayed optimum features, such as entrapment efficiency 97%, particle size 61.94 ± 0.11 µm, percentage yield 98%, swelling index 95% and mucoadhesiveness was 97%. FTIR studies revealed no major incompatibility between drug and excipients. SEM confirmed the particles were of spherical in shape. Optimized formulation (M12) were stable at 40°C ± 2°C/75% RH ± 5% RH for 6 months. In vivo studies were performed and kinetic parameters like Cmax, Tmax, AUC0-t, AUC0-∞, t1/2, and Kel  were calculated. The marketed product Cmax (3.15 ± 0.05 ng/mL) was higher than optimized formulation (2.58 ± 0.03 ng/mL). The optimized formulation AUC0-t (15.25 ± 1.14 ng.hr/mL), AUC0-∞ (19.42 ± 1.24 ng.hr/mL) was significantly higher than that of marketed product AUC0-t (10.21 ± 1.26 ng.hr/mL) and AUC0-∞ (13.15 ± 0.05 ng.hr/mL). These results indicate an optimized formulation bioavailability of 2.5-fold greater than marketed product.  


2020 ◽  
Vol 19 (17) ◽  
pp. 2108-2119
Author(s):  
Yang Jin ◽  
Li Lv ◽  
Shu-Xiang Ning ◽  
Ji-Hong Wang ◽  
Rong Xiao

Background: Laryngeal Squamous Cell Carcinoma (LSCC) is a malignant epithelial tumor with poor prognosis and its incidence rate increased recently. rLj-RGD3, a recombinant protein cloned from the buccal gland of Lampetra japonica, contains three RGD motifs that could bind to integrins on the tumor cells. Methods: MTT assay was used to detect the inhibitory rate of viability. Giemsa’s staining assay was used to observe the morphological changes of cells. Hoechst 33258 and TUNEL staining assay, DNA ladder assay were used to examine the apoptotic. Western blot assay was applied to detect the change of the integrin signal pathway. Wound-healing assay, migration, and invasion assay were used to detect the mobility of Hep2 cells. H&E staining assay was used to show the arrangement of the Hep2 cells in the solid tumor tissues. Results: In the present study, rLj-RGD3 was shown to inhibit the viability of LSCC Hep2 cells in vitro by inducing apoptosis with an IC50 of 1.23µM. Western blot showed that the apoptosis of Hep2 cells induced by rLj- RGD3 was dependent on the integrin-FAK-Akt pathway. Wound healing, transwells, and western blot assays in vitro showed that rLj-RGD3 suppressed the migration and invasion of Hep2 cells by integrin-FAKpaxillin/ PLC pathway which could also affect the cytoskeleton arrangement in Hep2 cells. In in vivo studies, rLj-RGD3 inhibited the growth, tumor volume, and weight, as well as disturbed the tissue structure of the solid tumors in xenograft models of BALB/c nude mice without reducing their body weights. Conclusion: hese results suggested that rLj-RGD3 is an effective and safe suppressor on the growth and metastasis of LSCC Hep2 cells from both in vitro and in vivo experiments. rLj-RGD3 might be expected to become a novel anti-tumor drug to treat LSCC patients in the near future.


2019 ◽  
Vol 20 (15) ◽  
pp. 3679 ◽  
Author(s):  
Lin Chen ◽  
Alyne Simões ◽  
Zujian Chen ◽  
Yan Zhao ◽  
Xinming Wu ◽  
...  

Wounds within the oral mucosa are known to heal more rapidly than skin wounds. Recent studies suggest that differences in the microRNAome profiles may underlie the exceptional healing that occurs in oral mucosa. Here, we test whether skin wound-healing can be accelerating by increasing the levels of oral mucosa-specific microRNAs. A panel of 57 differentially expressed high expresser microRNAs were identified based on our previously published miR-seq dataset of paired skin and oral mucosal wound-healing [Sci. Rep. (2019) 9:7160]. These microRNAs were further grouped into 5 clusters based on their expression patterns, and their differential expression was confirmed by TaqMan-based quantification of LCM-captured epithelial cells from the wound edges. Of these 5 clusters, Cluster IV (consisting of 8 microRNAs, including miR-31) is most intriguing due to its tissue-specific expression pattern and temporal changes during wound-healing. The in vitro functional assays show that ectopic transfection of miR-31 consistently enhanced keratinocyte proliferation and migration. In vivo, miR-31 mimic treatment led to a statistically significant acceleration of wound closure. Our results demonstrate that wound-healing can be enhanced in skin through the overexpression of microRNAs that are highly expressed in the privileged healing response of the oral mucosa.


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