GROWTH FACTORS AND COX2 IN WOUND HEALING: AN EXPERIMENTAL STUDY WITH EHRLICH TUMORS

Knockout Genes in Bowel Anastomoses: A Systematic Review of Literature Outcomes

BACKGROUND

The intestinal wound healing process is a complex event of three overlapping phases: exudative, proliferative, and remodeling. Although some mechanisms have been extensively described, the intestinal healing process is still not fully understood. There are some similarities but also some differences compared to other tissues. The aim of this systematic review was to summarize all studies with knockout (KO) experimental models in bowel anastomoses, underline any recent knowledge, and clarify further the cellular and molecular mechanisms of the intestinal healing process. A systematic review protocol was performed.

MATERIALS AND METHODS

Medline, EMBASE, and Scopus were comprehensively searched.

RESULTS

a total of eight studies were included. The silenced genes included interleukin-10, the four-and-one-half LIM domain-containing protein 2 (FHL2), cyclooxygenase-2 (COX-2), annexin A1 (ANXA-1), thrombin-activatable fibrinolysis inhibitor (TAFI), and heparin-binding epidermal growth factor (HB-EGF) gene. Surgically, an end-to-end bowel anastomosis was performed in the majority of the studies. Increased inflammatory cell infiltration in the anastomotic site was found in IL-10-, annexin-A1-, and TAFI-deficient mice compared to controls. COX-1 deficiency showed decreased angiogenesis at the anastomotic site. Administration of prostaglandin E2 in COX-2-deficient mice partially improved anastomotic leak rates, while treatment of ANXA1 KO mice with Ac2-26 nanoparticles reduced colitis activity and increased weight recovery following surgery.

CONCLUSIONS

our findings provide new insights into improving intestinal wound healing by amplifying the aforementioned genes using appropriate gene therapies. Further research is required to clarify further the cellular and micromolecular mechanisms of intestinal healing.

Green synthetized Cu-Oxide Nanoparticles: Properties and applications for enhancing healing of wounds infected with Staphylococcus aureus

Treating wound infections is a challenging concern in various clinical settings in Egypt, especially in the increasing global problem of resistance to antimicrobials. Here, we aimed to fabricate CuO NPs via green synthesis using aqueous Yucca gigantea extract. Then, the effect of green synthesized CuO NPs on Staphylococcus aureus clinical isolates has been studied in vivo and in vitro. The aqueous extract of Yucca gigantea has been employed in our study as a scale-up approach to safely, affordably, sustainably, and practically fabricate copper oxide nanoparticles (CuO NPs). Fourier transforms infrared (FT-IR), X-ray Diffraction (XRD), and UV-vis spectroscopy were utilized in vitro to describe the bonding features of CuO NPs.Scanning Electron microscopy (SEM), Transmission electron microscopy (TEM), Energy dispersive X-ray (EDX), and dynamic light scattering (DLS) were used to detect the morphological and elemental composition of the resulting CuO NPs. The fabrication of CuO NPs was confirmed by the IR spectral band at 515 cm-1, ensuring the metal-oxygen bondCu-O with two strong bands at 229 and 305 nm. SEM and TEM show CuO NPs with a size range from 30 to 50 nm. Cu and O comprised most of the particles produced through green synthesis, with weight percentages of 57.82 and 42.18 %, respectively. CuO NPs were observed to have a Zeta-potential value of -15.7 mV, demonstrating their great stability. CuO NPs revealed antibacterial potential toward the tested isolates with minimum inhibitory concentration values of 128 to 512 µg/mL. CuO NPs had antibiofilm potential by crystal violet assay, downregulating the expression of icaA and icaD genes in 23.07 % and 19.32 of the S. aureus isolates. The wound-healing potential of CuO NPs was investigated in vivo. It significantly decreased the bacterial burden and increased wound healing percentage compared to the positive control group. Moreover, CuO NPs caused an upregulation of the genes encoding platelet-derived growth factor (PDGF) and fibronectin in tissue repair. Thus, we can use CuO NPs as a future source for wound healing materials, especially in infected wounds.

Angiopoietin-1 derived peptide hydrogel promotes molecular hallmarks of regeneration and wound healing in dermal fibroblasts

By providing an ideal environment for healing, biomaterials can be designed to facilitate and encourage wound regeneration. As the wound healing process is complex, there needs to be consideration for the cell types playing major roles, such as fibroblasts. As a major cell type in the dermis, fibroblasts have a large impact on the processes and outcomes of wound healing. Prevopisly, conjugating the angiopoietin-1 derived Q-peptide (QHREDGS) to a collagen-chitosan hydrogel created a biomaterial with in vivo success in accelerating wound healing. This study utilized solvent cast Q-peptide conjugated collagen-chitosan seeded with fibroblast monolayers to investigate the direct impact of the material on this major cell type. After 24 h, fibroblasts had a significant change in release of anti-inflammatory, pro-healing, and ECM deposition cytokines, with demonstrated immunomodulatory effects on macrophages and upregulated expression of critical wound healing genes.

Co-delivery of gentiopicroside and thymoquinone using electrospun m-PEG/PVP nanofibers: In-vitro and In vivo studies for antibacterial wound dressing in diabetic rats

Nanofibers (NFs) provide several delivery advantages like their great flexibility and similarity with extracellular matrix (ECM) which qualify them to be the unique model of a wound dressing. NFs could create mats of polymeric matrix loaded with an active agent enhancing its solubility and stability. In our study, Gentiopicroside (GPS) and Thymoquinone (TQ) loaded in NFs polymeric mats composed of coblended polyvinyl pyrrolidine (PVP) and methyl ether Polyethylene glycol (m-PEG) were fabricated via electrospinning technique. A morphological study using Scanning Electron Microscopy (SEM) was performed for all formulae as well as in vitro release study using High-performance Liquid chromatography (HPLC) for sample analysis. The optimized formula (F3) was chosen for further assays using Fourier-Transform Infrared Spectroscopy (FTIR), and Differential Scanning Calorimetry (DSC). Study of the antibacterial effect, and in vivo healing action for diabetic infected wounds to quantify Tumor necrosis factor-alpha and Cyclooxygenase-2 were also investigated. F3 achieved the highest % cumulative release (99.79 ± 6.47 for GPS and 96.89 ± 6.87 for TQ) at 60 min, and a smaller diameter (200 nm) showing significant anti-bacterial effects with well-organized skin architecture demonstrating great healing signs. Our results revealed that m-PEG/PVP NFs mats loaded with GPS and TQ could be considered an optimal wound care dressing.

Encephalartos villosus Lem. Displays a Strong In Vivo and In Vitro Antifungal Potential against Candida glabrata Clinical Isolates

Recently, Candida glabrata has been recognized as one of the most common fungal species that is highly associated with invasive candidiasis. Its spread could be attributed to its increasing resistance to antifungal drugs. Thus, there is a high need for safer and more efficient therapeutic alternatives such as plant extracts. Here, we investigated the antifungal potential of Encephalartos villosus leaves methanol extract (EVME) against C. glabrata clinical isolates. Tentative phytochemical identification of 51 metabolites was conducted in EVME using LC–MS/MS. EVME demonstrated antifungal activity with minimum inhibitory concentrations that ranged from 32 to 256 µg/mL. The mechanism of the antifungal action was studied by investigating the impact of EVME on nucleotide leakage. Additionally, a sorbitol bioassay was performed, and we found that EVME affected the fungal cell wall. In addition, the effect of EVME was elucidated on the efflux activity of C. glabrata isolates using acridine orange assay and quantitative real-time PCR. EVME resulted in downregulation of the expression of the efflux pump genes CDR1, CDR2, and ERG11 in the tested isolates with percentages of 33.33%, 41.67%, and 33.33%, respectively. Moreover, we investigated the in vivo antifungal activity of EVME using a murine model with systemic infection. The fungal burden was determined in the kidney tissues. Histological and immunohistochemical studies were carried out to investigate the effect of EVME. We noticed that EVME reduced the congestion of the glomeruli and tubules of the kidney tissues of the rats infected with C. glabrata. Furthermore, it decreased both the proinflammatory cytokine tumor necrosis factor-alpha and the abnormal collagen fibers. Our results reveal, for the first time, the potential in vitro (by inhibition of the efflux activity) and in vivo (by decreasing the congestion and inflammation of the kidney tissues) antifungal activity of EVME against C. glabrata isolates.

Biological fabrication and electrostatic attractions of new layered silver/talc nanocomposite using Lawsonia inermis L. and its chitosan-capped inorganic/organic hybrid: Investigation on acceleration of Staphylococcus aureus and Pseudomonas aeruginosa infected wound healing

In the present study, new-layered inorganic/organic hybrid of silver/talc nanocomposites (Ag/Tlc-NPs) and its chitosan-capped derivative (Ag/Tlc/Csn NCs) were biochemically synthesized utilizing Lawsonia inermis L. extract. The silver nanoparticles (Ag NPs) were synthesized employing green method on the exterior surface layer of talc mineral as a solid substrate. The negatively charged surface layer of talc might function as templates and can attract the chitosan cations from a solution to yield a layered hybrid structure, whose inorganic phase is formed by Si-O-Ag bonds. Our results revealed that Ag NPs were formed on the exterior surface of talc with a diameter with size of 124-215 nm. In addition, cytotoxicity, in vitro antibacterial activity, and clinical effects of wound-healing ointments containing talc were investigated. The results implied the successful synthesis of Ag/Tlc/Csn NCs using the extract. The structures were safe up to 0.50 mg/mL. In vitro studies confirmed antioxidant and antibacterial properties of Ag/Tlc/Csn NCs. In sum, our findings showed that the ointments improve wound healing process by inducing an anti-inflammatory M2 phenotype and bFGF, CD206, collagen1A, and IL-10 production that causes fibroblast migration and wound closure through influencing M2 macrophage. Ag/Tlc/Csn is suggested to be taken into consideration as a medical combination for improving infected wound healing and as a promising agent for clinical administration.

PREVALENCE OF HEARING SYMPTOMS RELATED TO PATULOUS EUSTACHIAN TUBE AFTER BARIATRIC SURGERY

Background:

Rapid and severe weight loss can result in the reduction of the ear tube lining fat tissue and it becomes patent, leading to symptoms such as autophony, aural fullness and tinnitus. Patients after bariatric surgery have, in theory, a predisposition to the development of such alteration.

Aim:

To evaluate the presence of patent tuba-related complaints in patients undergoing bariatric surgery, correlating with weight and body mass index (BMI) values, as well as demographic data.

Methods:

Cross-sectional study composed of the evaluation of patients undergoing bariatric surgery through a standardized questionnaire about the presence of symptoms compatible with ear tube patency.

Results:

Eighty patients were evaluated, 77 female and three males. The main comorbidity was systemic arterial hypertension (37.5%). Fifteen (18.75%) presented symptoms compatible with patent auditory/Eustachian tube - aural fullness and autophony - postoperatively. In symptomatic individuals the initial weight was 112 kg on average and the preoperative BMI was 45 kg/m², while in asymptomatic individuals the weight was 117 kg and BMI 47 kg/m². There was statistical significance in the comparison between individuals with and without symptoms in the variables of initial weight (p=0.00000), current weight (p=0.00029), preoperative BMI (p=0.00219) and postoperative BMI (p=0.00148).

Conclusion:

The presence of symptoms compatible with patent auditory/Eustachian tube was 18.75% of the patients submitted to bariatric surgery in the evaluated sample. Both preoperative weight and BMI were lower in symptomatic patients when compared with the asymptomatic group.

EFFECTS OF PROBIOTICS SUPPLEMENTATION ON SKIN WOUND HEALING IN DIABETIC RATS

Background:

Chronic wounds in patients with Diabetes Mellitus often become incurable due to prolonged and excessive production of inflammatory cytokines. The use of probiotics modifies the intestinal microbiota and modulates inflammatory reactions.

Aim:

To evaluate the influence of perioperative supplementation with probiotics in the cutaneous healing process in diabetic rats.

Methods:

Forty-six rats were divided into four groups (C3, P3, C10, P10) according to the treatment (P=probiotic or C=control, both orally administered) and day of euthanasia, 3^rd or 10^th postoperative days. All rats were induced to Diabetes Mellitus 72 h before starting the experiment with alloxan. Supplementation was initiated five days before the incision and maintained until euthanasia. Scalpel incision was guided by a 2x2 cm mold and the wounds were left to heal per second-intention. The wounds were digitally measured. Collagen densitometry was done with Picrosirius Red staining. Histological parameters were analyzed by staining by H&E.

Results:

The contraction of the wound was faster in the P10 group which resulted in a smaller scar area (p=0.011). There was an increase in type I collagen deposition from the 3^rd to the 10^th postoperative day in the probiotic groups (p=0.016), which did not occur in the control group (p=0.487). The histological analysis showed a better degree of healing in the P10 group (p=0.005), with fewer polymorphonuclear (p<0.001) and more neovessels (p=0.001).

Conclusions:

Perioperative supplementation of probiotics stimulates skin wound healing in diabetic rats, possibly due to attenuation of the inflammatory response and increased neovascularization and type I collagen deposition.

Exosomes derived from TSG-6 modified mesenchymal stromal cells attenuate scar formation during wound healing

Mesenchymal stromal cell (MSC)-derived exosome therapy has emerged as an effective therapy strategy for the pathological scar formation. However, the underlying mechanisms have not been completely understood. In the current study, we investigate the therapeutic effect of TSG-6 modified MSC-derived exosomes on a mouse full-thickness wound model and provide evidence of a possible mechanism for MSC-derived exosomes to prevent from scar formation. Overexpression and knockdown of TSG-6 were conducted by lentivirus infection into hBMSCs. Exosomes were isolated from cell culture and identified by transmission electron microscopy and Western blot. C57BL/6J mice were performed of full-thickness skin wounds and treated with exosomal suspension or TSG-6-neutralizing antibody. H&E staining was subjected to observe the pathological changes of scar tissues. Immunohistochemistry, ELISA, real time-PCR and Western blot were applied to detect the expressions of relevant molecules. The results showed that subcutaneous injection of TSG-6 overexpressed MSC-derived exosomes effectively ameliorated scar pathological injury, decreased inflammatory molecular secretion and attenuated collagen deposition in a mouse skin wound model. Reversely, knockdown of TSG-6 abrogated the therapeutic effect of MSC-derived exosomes on scarring. Moreover, TSG-6-neutralizing antibody counteracted the effect of TSG-6 overexpressed MSC-derived exosomes in preventing scar formation. In conclusion, we demonstrated that exosomes derived from TSG-6 modified MSCs suppressed scar formation via reducing inflammation and inhibiting collagen deposition.

EFFECT OF PROBIOTIC ORAL ADMINISTRATION ON SKIN WOUND HEALING IN RATS

Background:

Manipulating intestinal microbiota with probiotics might stimulate skin response. Understanding all stages of the healing process, as well as the gut-skin-healing response can improve the skin healing process.

Aim:

To evaluate the effect of perioperative oral administration of probiotics on the healing of skin wounds in rats.

Methods:

Seventy-two Wistar male adult rats were weighed and divided into two groups with 36 each, one control group (supplemented with oral maltodextrin 250 mg/day) and one probiotic group (supplemented with Lactobacillus paracasei LPC-37, Bifidobacterium lactis HN0019, Lactobacillus rhamnosus HN001, Lactobacillus acidophilus NCFM^® at a dose of 250 mg/day), both given orally daily for 15 days. The two groups were subsequently divided into three subgroups according to the moment of euthanasia: in the 3^rd, 7^th and 10^th postoperative days.

Results:

There were no significant changes in weight in both groups. Wound contraction was faster in probiotic group when compared to the controls, resulting in smaller wound area in the 7^th postoperative day. As for histological aspects, the overall H&E score was lower in the probiotic group. The probiotic group showed increased fibrosis from 3^rd to the 7^th postoperative day. The type I collagen production was higher in the probiotic group at the 10^th postoperative day, and the type III collagen increased in the 7^th.

Conclusion:

The perioperative use of orally administrated probiotic was associated with a faster reduction of the wound area in rats probably by reducing the inflammatory phase, accelerating the fibrosis process and the deposition of collagen.

EFFECTS OF RENAL DYSFUNCTION ON HEALING OF COLONIC ANASTOMOSIS: EXPERIMENTAL STUDY IN WISTAR RATS

BACKGROUND

Chronic kidney disease affects more than 500 million people worldwide. In this context, the uremic toxins present are related to worsening in tissue healing.

AIM

Evaluate on healing of colonic anastomosis in uremic rats, serum and anatomopathological indicators, which may be related to the change tissue repair process.

METHODS

Twenty Wistar rats, were randomly separated into two groups. In the sham group they were submitted to 5/6 nephrectomy simulation in left kidney, simulation right nephrectomy, median laparotomy, colotomy and colorraphy. In the uremia group, they were submitted to 5/6 nephrectomy of the left kidney, total nephrectomy of the right kidney and median laparotomy, colotomy and colorraphy. Were collected for serum urea, creatinine and CRP dosages and the colonic segments were studied for evaluation of granulation tissue, collagen maturation, microvascular and myofibroblasts density, and cell viability. Through histochemical processing, microvascular density was evaluated by anti-CD34 monoclonal antibody marking, cell viability by cell proliferation nuclear antigen screening and myofibroblasts density with monoclonal anti-α-actin antibody. Computerized histometry was used for evaluations of collagens type I and III by the coloration of picrosirius.

RESULTS

The group submitted to nephrectomy 5/6, compared to the sham group, show urea increase (p<0.0000) and higher C reactive protein (p=0.0142). Decrease of granulation tissue formation (border reepithelialization p=0,0196, angiofibroblast proliferation p=0.0379), mean collagen I (p=0,0009) and collagen III (p=0,016), microvascular density (p=0,0074), cell proliferation nuclear antigen (p<0,0000) and myofibroblasts (p<0,0001).

CONCLUSION

The uremia induced by nephrectomy 5/6 model establishes negative impact in the colonic wound healing.