Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
Int J Mol Sci ; 24(14)2023 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-37510998

RESUMO

Environmental biophysical interactions are recognized to play an essential part in the human biological processes associated with trauma recovery. Many studies over several decades have furthered our understanding of the effects that Pulsed Electromagnetic Fields (PEMF) have on the human body, as well as on cellular and biophysical systems. These investigations have been driven by the observed positive clinical effects of this non-invasive treatment on patients, mainly in orthopedics. Unfortunately, the diversity of the various study setups, with regard to physical parameters, molecular and cellular response, and clinical outcomes, has made it difficult to interpret and evaluate commonalities, which could, in turn, lead to finding an underlying mechanistic understanding of this treatment modality. In this review, we give a birds-eye view of the vast landscape of studies that have been published on PEMF, presenting the reader with a scaffolded summary of relevant literature starting from categorical literature reviews down to individual studies for future research studies and clinical use. We also highlight discrepancies within the many diverse study setups to find common reporting parameters that can lead to a better universal understanding of PEMF effects.


Assuntos
Campos Eletromagnéticos , Magnetoterapia , Humanos
2.
Int J Mol Sci ; 24(6)2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36982967

RESUMO

Photobiomodulation, showing positive effects on wound healing processes, has been performed mainly with lasers in the red/infrared spectrum. Light of shorter wavelengths can significantly influence biological systems. This study aimed to evaluate and compare the therapeutic effects of pulsed LED light of different wavelengths on wound healing in a diabetic (db/db) mouse excision wound model. LED therapy by Repuls was applied at either 470 nm (blue), 540 nm (green) or 635 nm (red), at 40 mW/cm2 each. Wound size and wound perfusion were assessed and correlated to wound temperature and light absorption in the tissue. Red and trend-wise green light positively stimulated wound healing, while blue light was ineffective. Light absorption was wavelength-dependent and was associated with significantly increased wound perfusion as measured by laser Doppler imaging. Shorter wavelengths ranging from green to blue significantly increased wound surface temperature, while red light, which penetrates deeper into tissue, led to a significant increase in core body temperature. In summary, wound treatment with pulsed red or green light resulted in improved wound healing in diabetic mice. Since impeded wound healing in diabetic patients poses an ever-increasing socio-economic problem, LED therapy may be an effective, easily applied and cost-efficient supportive treatment for diabetic wound therapy.


Assuntos
Diabetes Mellitus Experimental , Terapia com Luz de Baixa Intensidade , Camundongos , Animais , Cicatrização , Fototerapia/métodos , Terapia com Luz de Baixa Intensidade/métodos , Luz
3.
Int J Mol Sci ; 23(16)2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-36012494

RESUMO

Acoustical biophysical therapies, including ultrasound, radial pressure waves, and shockwaves, have been shown to harbor both a destructive and regenerative potential depending on physical treatment parameters. Despite the clinical relevance of fungal biofilms, little work exits comparing the efficacy of these modalities on the destruction of fungal biofilms. This study evaluates the impact of acoustical low-frequency ultrasound, radial pressure waves, and shockwaves on the viability and proliferation of in vitro Rhizopus oryzae biofilm under Amphotericin B induced apoptosis. In addition, the impact of a fibrin substrate in comparison with a traditional polystyrene well-plate one is explored. We found consistent, mechanically promoted increased Amphotericin B efficacy when treating the biofilm in conjunction with low frequency ultrasound and radial pressure waves. In contrast, shockwave induced effects of mechanotransduction results in a stronger resilience of the biofilm, which was evident by a marked increase in cellular viability, and was not observed in the other types of acoustical pressure waves. Our findings suggest that fungal biofilms not only provide another model for mechanistical investigations of the regenerative properties of shockwave therapies, but warrant future investigations into the clinical viability of the therapy.


Assuntos
Anfotericina B , Tratamento por Ondas de Choque Extracorpóreas , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Biofilmes , Tratamento por Ondas de Choque Extracorpóreas/métodos , Mecanotransdução Celular , Testes de Sensibilidade Microbiana , Rhizopus oryzae
4.
Analyst ; 146(14): 4683-4699, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34195707

RESUMO

In this proof-of-principle study, we established and implemented a cross-modality imaging (CMI) pipeline to characterize and compare bisphosphonate (BIS)-treated jawbones of Sprague-Dawley rats after tooth extraction after physical therapies (photobiomodulation and extracorporeal shockwave therapy (PBMT and ESWT)). We showcase the feasibility of such a CMI approach and its compatibility across imaging modalities to probe the same region of interest (ROI) of the same jawbone. Jawbones were imaged in toto in 3D using micro-Computed Tomography to identify ROIs for subsequent sequential 2D analysis using well-established technologies such as Atomic Force Microscopy and Scanning Electron Microscopy, and recent imaging approaches in biomedical settings, such as micro-X-Ray Fluorescence Spectroscopy. By combining these four modalities, multiscale information on the morphology, topography, mechanical stiffness (Young's modulus), and calcium, zinc and phosphorus concentrations of the bone was collected. Based on the CMI pipeline, we characterized and compared the jawbones of a previously published clinically relevant rat model of BIS-related osteonecrosis of the jawbone (BRONJ) before and after treatment with BISs, PBMT and ESWT. While we did not find that physical therapies altered the mechanical and elemental jawbone parameters with significance (probably due to the small sample size of only up to 5 samples per group), both ESWT and PBMT reduced pore thicknesses and bone-to-enamel distances significantly compared to the controls. Although focused on BIS-treated jawbones, the established CMI platform can be beneficial in the study of bone-related diseases in general (such as osteoarthritis or -porosis) to acquire complementary hallmarks and better characterize disease status and alleviation potentials.


Assuntos
Tratamento por Ondas de Choque Extracorpóreas , Osteoartrite , Animais , Difosfonatos/toxicidade , Camundongos , Ratos , Ratos Sprague-Dawley , Microtomografia por Raio-X
5.
Cell Mol Life Sci ; 77(5): 885-901, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31278420

RESUMO

Purinergic P2 receptors are critical regulators of several functions within the vascular system, including platelet aggregation, vascular inflammation, and vascular tone. However, a role for ATP release and P2Y receptor signalling in angiogenesis remains poorly defined. Here, we demonstrate that blood vessel growth is controlled by P2Y2 receptors. Endothelial sprouting and vascular tube formation were significantly dependent on P2Y2 expression and inhibition of P2Y2 using a selective antagonist blocked microvascular network generation. Mechanistically, overexpression of P2Y2 in endothelial cells induced the expression of the proangiogenic molecules CXCR4, CD34, and angiopoietin-2, while expression of VEGFR-2 was decreased. Interestingly, elevated P2Y2 expression caused constitutive phosphorylation of ERK1/2 and VEGFR-2. However, stimulation of cells with the P2Y2 agonist UTP did not influence sprouting unless P2Y2 was constitutively expressed. Finally, inhibition of VEGFR-2 impaired spontaneous vascular network formation induced by P2Y2 overexpression. Our data suggest that P2Y2 receptors have an essential function in angiogenesis, and that P2Y2 receptors present a therapeutic target to regulate blood vessel growth.


Assuntos
Células Endoteliais/metabolismo , Endotélio Vascular/crescimento & desenvolvimento , Neovascularização Fisiológica/fisiologia , Receptores Purinérgicos P2Y2/metabolismo , Angiopoietina-2/biossíntese , Antígenos CD34/biossíntese , Células Cultivadas , Humanos , Proteína Quinase 1 Ativada por Mitógeno/biossíntese , Proteína Quinase 3 Ativada por Mitógeno/biossíntese , Fosforilação/fisiologia , Agregação Plaquetária/fisiologia , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Interferência de RNA , RNA Interferente Pequeno/genética , Receptores CXCR4/biossíntese , Receptores Purinérgicos P2Y2/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/biossíntese
6.
Int J Mol Sci ; 23(1)2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-35008735

RESUMO

In vitro investigations, which comprise the bulk of research efforts geared at identifying an underlying biomechanical mechanism for extracorporeal shock wave therapy (ESWT), are commonly hampered by inadequate descriptions of the underlying therapeutic acoustical pressure waves. We demonstrate the necessity of in-situ sound pressure measurements inside the treated samples considering the significant differences associated with available applicator technologies and cell containment. A statistical analysis of pulse-to-pulse variability in an electrohydraulic applicator yields a recommendation for a minimal pulse number of n = 300 for cell pallets and suspensions to achieve reproducible treatments. Non-linear absorption behavior of sample holders and boundary effects are shown for transient peak pressures and applied energies and may serve as a guide when in-situ measurements are not available or can be used as a controllable experimental design factor. For the use in microbiological investigations of ESWT we provide actionable identification of common problems in describing physical shockwave parameters and improving experimental setups by; (1) promoting in-situ sound field measurements, (2) statistical evaluation of applicator variability, and (3) extrapolation of treatment parameters based on focal and treatment volumes.


Assuntos
Tratamento por Ondas de Choque Extracorpóreas , Projetos de Pesquisa , Tecido Adiposo/citologia , Humanos , Pressão , Células Estromais/citologia
7.
Photochem Photobiol Sci ; 19(10): 1332-1343, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32996547

RESUMO

Rapidly evolving multidrug resistance renders conventional antimicrobial strategies increasingly inefficient. This urges the exploration of alternative strategies with a lower potential of resistance development to control microbial infections. A promising option is antimicrobial photodynamic therapy (aPDT), especially in the setting of wound infections. In this study its effectiveness was tested as a treatment option for polymicrobially infected wounds in both in vitro and in vivo models. First, aPDT was applied to wound-relevant Gram-positive and Gram-negative bacteria in planktonic culture as the standard in vitro test system and compared different media to show a possible dependency of the therapy on the surrounding environment. In a second step, aPDT was investigated in an in vitro model mimicking the wound bed conditions using fibrin-coated culture plates. Finally, we tested aPDT in vivo in a polymicrobial infected wound healing model in immunocompromised BALB/c mice. In vitro, it was shown that the bactericidal effectiveness of aPDT was strongly dependent on the surrounding environment of the phototoxic reaction. In vivo, the significant delay in wound healing induced by polymicrobial infection was drastically diminished by a two-times application of aPDT using 100 µM methylene blue (generally regarded as safe for topical application on human skin) and 24 J cm-2 pulsed red LED light. Our experiments suggest that aPDT is capable of significantly improving wound healing also in complicated polymicrobially infected wound situations.


Assuntos
Antibacterianos/farmacologia , Coinfecção/tratamento farmacológico , Coinfecção/microbiologia , Modelos Animais de Doenças , Escherichia coli K12/efeitos dos fármacos , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Staphylococcus capitis/efeitos dos fármacos , Animais , Antibacterianos/química , Feminino , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Fármacos Fotossensibilizantes/síntese química , Cicatrização/efeitos dos fármacos
8.
J Mater Sci Mater Med ; 29(6): 71, 2018 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-29796769

RESUMO

Two self-adhering hemostatic patches, based on either PEG-coated collagen (PCC) or PEG-coated oxidized cellulose (PCOC), are compared regarding to maximum burst pressure, mechanical stability, and swelling. In addition, the induction of tissue adhesions by the materials was assessed in a rabbit liver abrasion model. Both materials showed comparable sealing efficacy in a burst pressure test (37 ± 16 vs. 35 ± 8 mmHg, P = 0.730). After incubation in human plasma, PCC retained its mechanical properties over the test period of 8 h, while PCOC showed faster degradation after the 2 h time-point. The degradation led to a significantly decreased force at break (minimum force at break 0.55 N during 8 h for PCC, 0.27 N for PCOC; p < 0.001). Further, PCC allowed significantly higher deformation before break (52% after 4 h and 50% after 8 h for PCC, 18% after 4 h and 23% after 8 h for PCOC; p = 0.003 and p < 0.001 for 4 h and 8 h, respectively) and showed less swelling in human plasma (maximum increase in thickness: ~20% PCC, ~100% PCOC). Faster degradation of PCOC was visible macroscopically and histologically in vivo after 14 days. PCC showed visible structural residues with little cellular infiltration while strong infiltration with no remaining structural material was seen with PCOC. In vivo, a higher incidence of adhesion formation after PCOC application was detected. In conclusion, PCC has more reliable mechanical properties, reduced swelling, and less adhesion formation than PCOC. PCC may offer greater clinical benefit for surgeons in procedures that have potential risk for body fluid leakage or that require prolonged mechanical stability.


Assuntos
Celulose Oxidada/química , Celulose/química , Colágeno/química , Hemostáticos/química , Aderências Teciduais/prevenção & controle , Animais , Materiais Biocompatíveis/química , Adesão Celular , Hemostasia , Humanos , Fígado/patologia , Teste de Materiais , Oxigênio/química , Polietilenoglicóis/química , Pressão , Coelhos , Estresse Mecânico
9.
J Biol Chem ; 289(39): 27090-27104, 2014 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-25118288

RESUMO

Shock wave treatment accelerates impaired wound healing in diverse clinical situations. However, the mechanisms underlying the beneficial effects of shock waves have not yet been fully revealed. Because cell proliferation is a major requirement in the wound healing cascade, we used in vitro studies and an in vivo wound healing model to study whether shock wave treatment influences proliferation by altering major extracellular factors and signaling pathways involved in cell proliferation. We identified extracellular ATP, released in an energy- and pulse number-dependent manner, as a trigger of the biological effects of shock wave treatment. Shock wave treatment induced ATP release, increased Erk1/2 and p38 MAPK activation, and enhanced proliferation in three different cell types (C3H10T1/2 murine mesenchymal progenitor cells, primary human adipose tissue-derived stem cells, and a human Jurkat T cell line) in vitro. Purinergic signaling-induced Erk1/2 activation was found to be essential for this proliferative effect, which was further confirmed by in vivo studies in a rat wound healing model where shock wave treatment induced proliferation and increased wound healing in an Erk1/2-dependent fashion. In summary, this report demonstrates that shock wave treatment triggers release of cellular ATP, which subsequently activates purinergic receptors and finally enhances proliferation in vitro and in vivo via downstream Erk1/2 signaling. In conclusion, our findings shed further light on the molecular mechanisms by which shock wave treatment exerts its beneficial effects. These findings could help to improve the clinical use of shock wave treatment for wound healing.


Assuntos
Trifosfato de Adenosina/metabolismo , Proliferação de Células , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Ondas de Choque de Alta Energia , Sistema de Sinalização das MAP Quinases , Cicatrização , Adulto , Animais , Ativação Enzimática , MAP Quinases Reguladas por Sinal Extracelular/genética , Feminino , Humanos , Células Jurkat , Masculino , Camundongos , Ratos , Ratos Sprague-Dawley
10.
Lasers Surg Med ; 46(10): 773-80, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25363448

RESUMO

BACKGROUND AND OBJECTIVE: Low-level light therapy (LLLT) has been revealed as a potential means to improve wound healing. So far, most studies are being performed with irradiation in the red to near-infrared spectra. Recently, we showed that blue light (470 nm) can significantly influence biological systems such as nitric oxide (NO) metabolism and is able to release NO from nitrosyl-hemoglobin or mitochondrial protein complexes. Therefore, the aim of this study was to evaluate and compare the therapeutic value of blue or red light emitting diodes (LEDs) on wound healing in an ischemia disturbed rodent flap model. STUDY DESIGN/MATERIALS AND METHODS: An abdominal flap was rendered ischemic by ligation of one epigastric bundle and subjected to LED illumination with a wavelength of 470 nm (blue, n = 8) or 629 nm (red, n = 8) each at 50 mW/cm(2) and compared to a non-treated control group (n = 8). Illumination was performed for 10 minutes on five consecutive days. RESULTS: LED therapy with both wavelengths significantly increased angiogenesis in the sub-epidermal layer and intramuscularly (panniculus carnosus muscle) which was associated with significantly improved tissue perfusion 7 days after the ischemic insult. Accordingly, tissue necrosis was significantly reduced and shrinkage significantly less pronounced in the LED-treated groups of both wavelengths. CONCLUSIONS: LED treatment of ischemia challenged tissue improved early wound healing by enhancing angiogenesis irrespective of the wavelength thus delineating this noninvasive means as a potential, cost effective tool in complicated wounds.


Assuntos
Isquemia/radioterapia , Neovascularização Fisiológica/efeitos da radiação , Fototerapia/instrumentação , Retalhos Cirúrgicos/irrigação sanguínea , Cicatrização/efeitos da radiação , Abdome , Animais , Modelos Animais de Doenças , Isquemia/etiologia , Isquemia/patologia , Ligadura , Masculino , Ratos , Ratos Sprague-Dawley
11.
Int J Biol Macromol ; 275(Pt 1): 133584, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38960271

RESUMO

The Helicobacter pylori infection in the stomach is the key reason for gastric mucosal bleeding. Eliminating gastric Helicobacter pylori by oral treatment remains difficult due to the presence of the gastric mucosal layer, which acts as a physical barrier to drugs via oral administration. In this study, a magnetic-navigable microneedle drug delivery platform (MNsD) for oral administration, featuring differential dual-mode drug release rate, was designed to fulfil rapid gastric hemostasis and overcome the gastric barriers for long-lasting Helicobacter pylori inhibition in stomach. MNs-D was created by rationally loading the carrier substrate, which was composed of silk fibroin with variable solubility, with antibiotics and hemostats. In vitro experiments showed MNs-D may sustainably eradicate Helicobacter pylori in stimulated gastric juices with long-lasting drug release (79 % in 24 h) and quickly establish hemostasis with instant drug release (92 % within 60 s). Most importantly, in vivo studies demonstrated MNs-D overcame the unsettling gastric mucosal barrier in traditional therapies of oral administration by insertion into the GML under magnetic navigation, resulting in sustained antibiotic release for long-lasting Helicobacter pylori eradiation (99 %). For differential dual-mode medication release against gastric Helicobacter pylori infections, this study may have firstly examined the effects of magnetic navigated microneedles administered orally.

12.
Research (Wash D C) ; 7: 0388, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38812529

RESUMO

Thrombosis can cause life-threatening disorders. Unfortunately, current therapeutic methods for thrombosis using injecting thrombolytic medicines systemically resulted in unexpected bleeding complications. Moreover, the absence of practical imaging tools for thrombi raised dangers of undertreatment and overtreatment. This study develops a theranostic drug carrier, Pkr(IR-Ca/Pda-uPA)-cRGD, that enables real-time monitoring of the targeted thrombolytic process of deep vein thrombosis (DVT). Pkr(IR-Ca/Pda-uPA)-cRGD, which is prepared from a Pickering-emulsion-like system, encapsulates both near-infrared-II (NIR-II) contrast agent (IR-1048 dye, loading capacity: 28%) and urokinase plasminogen activators (uPAs, encapsulation efficiency: 89%), pioneering the loading of multiple drugs with contrasting hydrophilicity into one single-drug carrier. Upon intravenous injection, Pkr(IR-Ca/Pda-uPA)-cRGD considerably targets to thrombi selectively (targeting rate: 91%) and disintegrates in response to acidic thrombi to release IR-1048 dye and uPA for imaging and thrombolysis, respectively. Investigations indicate that Pkr(IR-Ca/Pda-uPA)-cRGD enabled real-time visualization of targeted thrombolysis using NIR-II imaging in DVT models, in which thrombi were eliminated (120 min after drug injection) without bleeding complications. This may be the first study using convenient NIR-II imaging for real-time visualization of targeted thrombolysis. It represents the precision medicine that enables rapid response to acquire instantaneous medical images and make necessary real-time adjustments to diagnostic and therapeutic protocols during treatment.

13.
J Biomed Mater Res A ; 111(4): 488-501, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36355631

RESUMO

Fibrin sealants are well-established components of the surgical toolbox, especially in procedures that harbor a high risk of perioperative bleeding. Their widespread use as hemostats, sealants or tissue-adhesives in various surgical settings has shown that the choice of the appropriate sealant system affects the clinical outcome. While many studies have compared the hemostatic efficiency of fibrin sealants to that of other natural or synthetic sealants, there is still limited data on how subtle differences in fibrin sealant formulations relate to their biological performance. Here, we performed an in-depth physicochemical and biological characterization of the two most commonly used fibrin sealants in the US and Europe: TISSEEL™ ("FS") and VISTASEAL™/VERASEAL™ ("FS+Osm"). Our chemical analyses demonstrated differences between the two sealants, with lower fibrinogen concentrations and supraphysiological osmolality in the FS+Osm formulation. Rheological testing revealed FS clots have greater clot stiffness, which strongly correlated with network density. Ultrastructural analysis by scanning electron microscopy revealed differences between FS and FS+Osm fibrin networks, the latter characterized by a largely amorphous hydrogel structure in contrast to the physiological fibrillar network of FS. Cytocompatibility experiments with human fibroblasts seeded on FS and FS+Osm fibrin networks, or cultured in presence of sealant extracts, revealed that FS+Osm induced apoptosis, which was not observed with FS. Although differential sealant osmolality and amounts of fibrinogen, as well as the presence of Factor XIII or additives such as antifibrinolytics, may explain the mechanical and structural differences observed between the two fibrin sealants, none of these substances are known to cause apoptosis at the respective concentrations in the sealant formulation. We thus conclude that hyper osmolality in the FS+Osm formulation is the primary trigger of apoptosis-a mechanism that should be evaluated in more detail, as it may affect the cellular wound healing response in situ.


Assuntos
Hemostáticos , Adesivos Teciduais , Humanos , Adesivo Tecidual de Fibrina/análise , Adesivo Tecidual de Fibrina/química , Adesivo Tecidual de Fibrina/farmacologia , Hemostáticos/farmacologia , Cicatrização , Adesivos Teciduais/química , Fibrinogênio/farmacologia
14.
Biomedicines ; 11(4)2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-37189661

RESUMO

Chronic wounds remain a serious clinical problem with insufficient therapeutic approaches. In this study we investigated the dose dependency of rhVEGF165 in fibrin sealant in both ischemic and non-ischemic excision wounds using our recently developed impaired-wound healing model. An abdominal flap was harvested from the rat with unilateral ligation of the epigastric bundle and consequent unilateral flap ischemia. Two excisional wounds were set in the ischemic and non-ischemic area. Wounds were treated with three different rhVEGF165 doses (10, 50 and 100 ng) mixed with fibrin or fibrin alone. Control animals received no therapy. Laser Doppler imaging (LDI) and immunohistochemistry were performed to verify ischemia and angiogenesis. Wound size was monitored with computed planimetric analysis. LDI revealed insufficient tissue perfusion in all groups. Planimetric analysis showed slower wound healing in the ischemic area in all groups. Wound healing was fastest with fibrin treatment-irrespective of tissue vitality. Lower dose VEGF (10 and 50 ng) led to faster wound healing compared to high-dose VEGF. Immunohistochemistry showed the highest vessel numbers in low-dose VEGF groups. In our previously established model, different rhVEGF165 treatments led to dose-dependent differences in angiogenesis and wound healing, but the fastest wound closure was achieved with fibrin matrix alone.

16.
Surg Infect (Larchmt) ; 24(1): 82-90, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36706256

RESUMO

Background: Fibrin sealants are used as antimicrobial-releasing carriers for preventing surgical site infections; however, it is important to determine the release kinetics and antimicrobial effects of drugs added to fibrin sealants and the effects of drugs on clot/clotting properties. Materials and Methods: The antimicrobial and antibiofilm activity of cefazolin, colistin, gentamicin, oxacillin, tobramycin, and silver nitrate released from fibrin sealant were characterized using in vitro and ex vivo assays against bacteria commonly found on the skin. The effects of antimicrobial agents on the physical structure of the fibrin sealant were assessed with scanning electron microscopy (SEM) and on the clotting rate and strength of fibrin clots using run-off tests and rheology. Results: Generally, antibiotic agents were released gradually from fibrin sealant and were stable after release, with antimicrobial effects evident up to three days. Cefazolin, gentamicin, and oxacillin prevented biofilm formation of Staphylococcus aureus in porcine skin explants; gentamicin and colistin prevented biofilm formation of Pseudomonas aeruginosa. Gentamicin, cefazolin, colistin, and tobramycin did not affect the structural integrity or viscoelastic properties of fibrin sealant; changes were observed with oxacillin (SEM) and particularly silver nitrate (SEM and rheology). No antimicrobial agents caused deterioration of clotting time (run-off tests). Conclusions: From the antimicrobial agents tested, gentamicin and cefazolin showed prolonged release from fibrin sealant, sustained antimicrobial activity, and biofilm prevention properties against Staphylococcus aureus; similar results were observed for gentamicin and colistin against Pseudomonas aeruginosa. For each of these findings, the physical structure of the fibrin sealant, clotting rate, and strength of fibrin clots were unaffected.


Assuntos
Adesivo Tecidual de Fibrina , Infecções Estafilocócicas , Animais , Suínos , Adesivo Tecidual de Fibrina/farmacologia , Adesivo Tecidual de Fibrina/química , Cefazolina , Colistina , Nitrato de Prata , Antibacterianos/uso terapêutico , Gentamicinas/farmacologia , Oxacilina , Tobramicina , Infecções Estafilocócicas/tratamento farmacológico
17.
Sci Rep ; 13(1): 22985, 2023 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-38151564

RESUMO

Burn wounds are a common challenge for medical professionals. Current burn wound models hold several limitations, including a lack of comparability due to the heterogeneity of wounds and differences in individual wound healing. Hence, there is a need for reproducible in vivo models. In this study, we established a new burn wound model using the chorioallantoic membrane assay (CAM) as a surrogate model for animal experiments. The new experimental setup was tested by investigating the effects of the auspicious biophysical therapy, photobiomodulation (PBM), on the wound healing of an induced CAM burn wound with a metal stamp. PBM has been shown to positively influence wound healing through vascular proliferative effects and the increased secretion of chemotactic substances. The easily accessible burn wounds can be treated with various therapies. The model enables the analysis of ingrowing blood vessels (angiogenesis) and diameter and area of the wounds. The established model was used to test the effects of PBM on burn wound healing. PBM promoted angiogenesis in burn wounds on day 4 (p = 0.005). Furthermore, there was a not significant trend toward a higher number of vessels for day 6 (p = 0.065) in the irradiated group. Changes in diameter (p = 0.129) and the burn area (p = 0.131) were not significant. Our results suggest that CAM can be a suitable model for studying burn wounds. The novel experimental design enables reproducible and comparable studies on burn wound treatment.


Assuntos
Queimaduras , Terapia com Luz de Baixa Intensidade , Animais , Membrana Corioalantoide , Angiogênese , Cicatrização , Queimaduras/radioterapia
18.
Dev Cell ; 58(11): 981-992.e6, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37098351

RESUMO

The spatial boundaries of tissue response to wounding are unknown. Here, we show that in mammals, the ribosomal protein S6 (rpS6) is phosphorylated in response to skin injury, forming a zone of activation surrounding the region of the initial insult. This p-rpS6-zone forms within minutes after wounding and is present until healing is complete. The zone is a robust marker of healing as it encapsulates features of the healing process, including proliferation, growth, cellular senescence, and angiogenesis. A mouse model that is unable to phosphorylate rpS6 shows an initial acceleration of wound closure, but results in impaired healing, identifying p-rpS6 as a modulator but not a driver of healing. Finally, the p-rpS6-zone accurately reports on the status of dermal vasculature and the effectiveness of healing, visually dividing an otherwise homogeneous tissue into regions with distinct properties.


Assuntos
Mamíferos , Animais , Camundongos , Mamíferos/metabolismo , Fosforilação , Proteína S6 Ribossômica/metabolismo , Cicatrização/genética , Cicatrização/fisiologia
19.
Biomedicines ; 10(6)2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35740477

RESUMO

The potential beneficial regenerative and stimulatory extracorporeal shock wave therapy (ESWT) applications to the central nervous system have garnered interest in recent years. Treatment zones for these indications are acoustically shielded by bones, which heavily impact generated sound fields. We present the results of high-resolution tissue-realistic simulations, comparing the viability of different ESWT applicators in their use for transcranial applications. The performances of electrohydraulic, electromagnetic, and piezoelectric transducers for key reflector geometries are compared. Based on density information obtained from CT imaging of the head, we utilized the non-linear wave propagation toolset Matlab k-Wave to obtain spatial therapeutic sound field geometries and waveforms. In order to understand the reliability of results on the appropriate modeling of the skull, three different bone attenuation models were compared. We find that all currently clinically ESWT applicator technologies show significant retention of peak pressures and energies past the bone barrier. Electromagnetic transducers maintain a significantly higher energy flux density compared to other technologies while low focusing strength piezoelectric applicators have the weakest transmissions. Attenuation estimates provide insights into sound field degradation and energy losses, indicating that effective transcranial therapies can readily be attained with current applicators. Furthermore, the presented approach will allow for future targeted in silico development and the design of applicators and therapy plans to ultimately improve therapeutic outcomes.

20.
J Clin Med ; 11(7)2022 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-35407594

RESUMO

A delay or failure to heal is the most common possible complication in clavicle fractures, especially in cases primarily treated conservatively. As the current standard therapy, surgical revision achieves good healing results, but is associated with potential surgery-related complications. Shockwave therapy as a non-invasive therapy shows similar reasonable consolidation rates in the non-union of different localizations, but avoids complications. Compromised clavicle fractures in the middle and lateral third treated with focused high-energy shockwave therapy were compared with those treated with surgical revision (ORIF). In addition, a three-dimensional computer simulation for evaluating the pressure distribution during shockwave application accompanied the clinical study. A comparable healing rate in bony consolidation was achieved in both groups. Significantly fewer complications, however, occurred in the shockwave group. The simulations showed safe application in this instance, particularly in avoiding lung tissue affection. When applied correctly, shockwaves represent a safe and promising therapy option for compromised clavicle fractures in the middle and lateral third.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA