An Open-Label Study of Low-Level Laser Therapy Followed by Autologous Fibroblast Transplantation for Healing Grade 3 Burn Wounds in Diabetic Patients

Estudo pré-clínico de queimaduras experimentais tratadas com fotobiomodulação e membrana amniótica humana, isoladas e associadas

Resumo Objetivo: avaliar o efeito da fotobiomodulação com laser de baixa intensidade 660 nm isoladamente ou associada à membrana amniótica humana no reparo de queimaduras de espessura parcial em ratos. Método: estudo experimental com 48 ratos Wistar machos, randomizados em quatro grupos: Controle, Membrana Amniótica Humana, Terapia a Laser de Baixa Intensidade e Terapia a Laser de Baixa Intensidade associado à Membrana Amniótica Humana. As características histopatológicas das amostras de pele foram analisadas aos 7 e 14 dias após a queimadura. Os dados obtidos foram submetidos aos testes de Kolmogorov-Smirnov e Mann Whitney. Resultados: a análise histológica das lesões por queimadura mostrou a diminuição da inflamação (p <0,0001) e aumento da proliferação de fibroblastos (p <0,0001), principalmente nos 7 dias em todos os tratamentos relacionados ao grupo controle. Aos 14 dias, a maior efetividade na aceleração do processo cicatricial foi significativa (p<0,0001) no grupo Terapia a Laser de Baixa Intensidade associado à Membrana Amniótica Humana. Conclusão: a associação das terapias de fotobiomodulação à membrana amniótica humana permitiu comprovar redução no tempo do processo cicatricial das lesões experimentais, estimulando sua proposição como protocolo de tratamento em queimaduras de espessura parcial.

Estudio preclínico de quemaduras experimentales tratadas con fotobiomodulación y membrana amniótica humana, solas y combinadas

Resumen Objetivo: evaluar el efecto de la fotobiomodulación con láser de baja intensidad 660 nm de sola o combinada con la membrana amniótica humana en la reparación de quemaduras de espesor parcial en ratas. Método: estudio experimental con 48 ratas Wistar macho, aleatorizadas en cuatro grupos: Control, Membrana Amniótica Humana, Terapia con Láser de Baja Intensidad y Terapia con Láser de Baja Intensidad combinada con la Membrana Amniótica Humana. Las características histopatológicas de las muestras de piel fueron analizadas a los 7 y 14 días después de la quemadura. Los datos obtenidos fueron sometidos a las pruebas de Kolmogorov-Smirnov y Mann-Whitney. Resultados: el análisis histológico de las lesiones por quemadura mostró una disminución de la inflamación (p <0,0001) y un aumento de la proliferación de fibroblastos (p <0,0001) principalmente a los 7 días en todos los tratamientos en comparación con el grupo control; a los 14 días, en el grupo de Terapia con Láser de Baja Intensidad combinada con la Membrana Amniótica Humana la mayor efectividad en la aceleración del proceso de cicatrización fue significativa (p<0,0001). Conclusión: la asociación de terapias de fotobiomodulación con la membrana amniótica humana permitió comprobar que hubo una reducción en el tiempo del proceso de cicatrización de lesiones experimentales, lo cual favorece que se proponga como protocolo de tratamiento en quemaduras de espesor parcial.

Preclinical study of experimental burns treated with photobiomodulation and Human Amniotic Membrane, both isolated and associated

OBJECTIVE

to evaluate the effect of photobiomodulation with low-level 660 nm laser alone or associated with Human Amniotic Membrane in the repair of partial-thickness burns in rats.

METHOD

an experimental study conducted with 48 male Wistar rats, randomized into four groups: Control, Human Amniotic Membrane, Low-Level Laser Therapy, and Low-Level Laser Therapy associated with Human Amniotic Membrane. The histopathological characteristics of the skin samples were analyzed 7 and 14 days after the burn. The data obtained were submitted to the Kolmogorov-Smirnov and Mann-Whitney tests.

RESULTS

the histological analysis of the burn injuries showed a decrease in inflammation (p<0.0001) and an increase in proliferation of fibroblasts (p<0.0001) mainly at 7 days in all treatments related to the control group. At 14 days, the greater effectiveness in accelerating the healing process was significant (p<0.0001) in the Low-Level Laser Therapy group associated with the Human Amniotic Membrane.

CONCLUSION

the association of photobiomodulation therapies with the Human Amniotic Membrane allowed verifying a reduction in the healing process time of the experimental lesions, stimulating its proposal as a treatment protocol in partial-thickness burns.

Low-level laser therapy is effective in controlling postoperative pain in lower third molar extractions: a systematic review and meta-analysis

This systematic review aimed to evaluate the effectiveness of low-level laser therapy in controlling postoperative pain in lower third molar extractions. A search was carried out in MEDLINE/PubMed, Web of Science and Cochrane Library (CENTRAL) databases, using the "low-level laser therapy", "photobiomodulation therapy", "impacted mandibular third molar", "mandibular third molar", "third molar extraction" descriptors and 2625 studies were found, including only randomized clinical trials published until July 2020, with no restrictions on language and country of study. Selected studies were submitted to initial screening based on the reading of titles, abstracts and full article, and duplicate studies were excluded. Overall, 2562 articles were found, of which only 15 randomized clinical trials were included in this review. A total of 648 patients (16-44 years) who received low-level laser therapy as an intervention and placebo in their control group were evaluated. The pain evaluation criterion was the Visual Analog Scale (VAS) on the second and seventh days after surgery. Photobiomodulation with low-level laser showed statistically significant reduction in postoperative pain in lower third molar extractions, both on the second (MD: - 0.59; CI: - 0.92, - 0.27) and seventh day after surgery (MD: - 0.76; CI: - 1.21, - 0.32).

MicroRNA-133b Inhibition Restores EGFR Expression and Accelerates Diabetes-Impaired Wound Healing

Diabetic foot ulcers (DFUs) are caused by impairments in peripheral blood vessel angiogenesis and represent a great clinical challenge. Although various innovative techniques and drugs have been developed for treating DFUs, therapeutic outcomes remain unsatisfactory. Using the GEO database, we obtained transcriptomic microarray data for DFUs and control wounds and detected a significant downregulation of epidermal growth factor receptor (EGFR) in DFUs. We cultured human umbilical vein endothelial cells (HUVECs) and noted downregulated EGFR expression following high-glucose exposure in vitro. Further, we observed decreased HUVEC proliferation and migration and increased apoptosis after shRNA-mediated EGFR silencing in these cells. In mice, EGFR inhibition via focal EGFR-shRNA injection delayed wound healing. Target prediction analysis followed by dual-luciferase reporter assays indicated that microRNA-133b (miR-133b) is a putative upstream regulator of EGFR expression. Increased miR-133b expression was observed in both glucose-treated HUVECs and wounds from diabetes patients, but no such change was observed in controls. miR-133b suppression enhanced the proliferation and angiogenic potential of cultured HUVECs and also accelerated wound healing. Although angiogenesis is not the sole mechanism affected in DFU, these findings suggest that the miR-133b-induced downregulation of EGFR may contribute to delayed wound healing in diabetes. Hence, miR-133b inhibition may be a useful strategy for treating diabetic wounds.

Biological Characteristics and Optical Reflectance Spectroscopy of Human Placenta Derived Mesenchymal Stem Cells for Application in Regenerative Medicine

Introduction: The efficiency of stem cell isolation, culture, and biological characterization techniques for treatment is facing serious challenges. The purpose of this study was to provide a protocol for isolation and culture of three types of mesenchymal stem cells (MSCs) derived from the human placenta, amniotic membrane, and umbilical cord with high efficiency used for cell therapy. Methods: During this experimental laboratory study, 10 complete placenta samples were prepared from cesarean section mothers. The protocol for isolation and culture of mesenchymal cells from the placenta tissue, umbilical cord, and amniotic membrane was enzymatically optimized. The morphological features of mesenchymal cells were investigated using an inverted microscope and their biological features were measured using flow cytometry. The differentiation potential of the cells was evaluated by measuring their differentiation capacity into osteocytes and adipocytes. The absorption and reflectance features of the cells were recorded by optical spectroscopy. Finally, the data were statistically analyzed. Results: The expression of CD44, CD73, CD90 and CD29 markers in human placenta tissue-derived cells was significant. CD14, CD34 and CD45 markers were not expressed or were slightly expressed. These cells were highly viable and successfully differentiated into osteocytes and adipocytes. MSCs absorbed more light than visible light by showing light absorption peaks at wavelengths of about 435 and 550 nm. Conclusion: The protocol used in this study for isolation and culture of human placenta tissue-derived MSCs had significant efficiency for the production of MSCs for use in cell therapy and tissue engineering.

Effects of photobiomodulation on wound contraction in rats undergoing doxorubicin extravasation: a histomorphometric analysis

OBJECTIVE

To analyze wound contraction and histomorphometric pattern of lesions in Wistar rats undergoing doxorubicin extravasation.

METHOD

Sixty adult female rats were used, divided into four groups of fifteen animals: Group 1 (Control, without antidote); Group 2 (Hyaluronidase); Group 3 (Photobiomodulation), and Group 4 (Hyaluronidase + Photobiomodulation). Doxorubicin 1mg (0.5 ml) was applied subcutaneously on the animals' back, inducing the wound. Macroscopic and morphometric evaluation of the lesions was performed every two days for 28 days. On the 30th day, euthanasia was performed and the material was collected for histological evaluation.

RESULTS

The animals in the photobiomodulation and photobiomodulation + Hyaluronidase groups presented regeneration tissue with neovascularization and acute inflammation, with improvement in wound healing, which did not occur in the other groups. The contraction rates were better in those treated with photobiomodulation and photobiomodulation + Hyaluronidase, with healing percentages of 76.6% and 72.1%, respectively.

CONCLUSION

The combination of photobiomodulation (660 nm-1 J) with topical hyaluronidase (65 UTR) proved to be effective in the process of wound healing due to extravasation of doxorubicin, and can be incorporated into the practice of clinical oncology.

Clinical effects of high-intensity laser therapy on patients with chronic refractory wounds: a randomised controlled trial

OBJECTIVE

To investigate the effectiveness of high-intensity laser therapy (HILT) on chronic refractory wounds.DesignRandomised controlled trial.

SETTING

The outpatient wound care department of the Affiliated Jiangsu Shengze Hospital of Nanjing Medical University from August 2019 to June 2020.

PARTICIPANTS

Sixty patients were enrolled in this study and were randomised into control (n=30) and treatment (n=30) groups.

INTERVENTIONS AND OUTCOME MEASURES

The control group was treated only with conventional wound dressing, whereas the treatment group received irradiation with HILT in addition to standard wound care, such as debridement, wound irrigation with normal saline solution and application of dressing and sterile gauze. Patient scores on the Bates-Jensen Wound Assessment Tool (BWAT) and Pressure Ulcer Scale for Healing (PUSH) were evaluated before and after 1, 2 and 3 weeks of treatment.

RESULTS

One patient was excluded from the control group, and a total of 59 subjects completed the trial. The BWAT scores significantly decreased in the treatment group compared with the control group at the end of 3-week treatment (difference=-3.6; 95% CI -6.3 to-0.8; p<0.01). Similarly, patients in treatment group showed a significant reduction of PUSH scores compared with the control group (difference=-5.3; 95% CI -8.1 to -2.6; p<0.01).

CONCLUSIONS

The therapeutic effects of HILT on chronic refractory wounds are significant and far more superior to those of conventional wound dressing.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry; ChiCTR1900023157. URL: http://www.chictr.org.cn/showproj.aspx?proj=38866.

Photobiomodulation in diabetic wound healing: A review of red and near-infrared wavelength applications

The development of a painless, non-invasive, and faster way to diabetic wound healing is at the forefront of research. The complexity associated with diabetic wounds makes it a cause for concern amongst diabetic patients and the world at large. Irradiation of cells generates a photobiomodulatory response on cells and tissues, directly causing alteration of cellular processes and inducing diabetic wound repair. Photobiomodulation therapy (PBMT) using red and near-infrared (NIR) wavelengths is being considered as a promising technique for speeding up the rate of diabetic wound healing, eradication of pain and reduction of inflammation through the alteration of diverse cellular and molecular processes. This review presents the extent to which the potential of red and NIR wavelengths have been harnessed in PBMT for diabetic wound healing. Important research challenges and gaps are identified and discussed, and future directions mapped out. This review thus provides useful insights and strategies into improvement of PBMT, including its acceptance within the global medical research community.

Effects of intravenous and transdermal photobiomodulation on the postoperative complications of coronary artery bypass grafting surgery: a randomized, controlled clinical trial

Although coronary artery bypass graft (CABG) surgery is one of the most worldwide commonly performed cardiac surgeries to enhance myocardial perfusion in high-grade myocardial occlusion, it remains a high-risk procedure. Photobiomodulation (PBM) is one of the methods which have been shown to have positive effects on the healing process after CABG and postoperative complications. The aim of this study was to evaluate the efficacy of PBM in patients who underwent a coronary artery bypass graft (CABG). Ths study was conducted with 192 volunteers who electively submitted to CABG. The volunteers were randomly allocated into two groups: laser-treated (transdermal: 980 nm, 200 mW, continuous, average energy fluency of 6 J/cm² and intravenous: 405 nm, 1.5 mW, continuous for 30 min) and standard treatment and control group (standard treatment only). Intravenous laser was illuminated the day before the surgery, immediately after transferring the patient to CCU post-operation and IV laser in addition to transdermal laser was applied every day after surgery for 6 days. A total of 170 out of 192 participants completed the study, 82 (48.2%) in the PBM group and 88 (51.8%) in the control group. Level of LDH and CPK was significantly lower in the PBM group (P < 0.05) in the 4th day postoperatively. The PBM group also showed significantly lower post-surgery complications, including pericardial effusion, ejection fraction, pathologic ST changes, pathologic Q, rehospitalization, heart failure, and mediastinitis (P < 0.05). Likewise, the VAS pain score after surgery was significantly lower in patients in the laser group (P < 0.05). PBM seems a promising, safe, cost-benefit therapeutic modality to reduce postoperative complications of CABG. Trial registration number: IRCT2016052926069N4 .

Biostimulative effect of laser on growth of mesenchymal stem/stromal cells in vitro

Introduction

Human adipose tissue-derived mesenchymal stem/stromal cells (hAT-MSCs) are multipotent stromal cells with a high potential application in tissue engineering and regenerative medicine. Laser irradiation of the place where the cells were implanted can stimulate their proliferation, increase the secretion of growth factors and thus increase the therapeutic effect.

Aim

To evaluate the influence of two lasers: Er:YAG and diode on the growth of hAT-MSCs in vitro.

Material and methods

hAT-MSCs were isolated from human subcutaneous adipose tissue. Immunophenotype of hAT-MSCs was confirmed by flow cytometry. Multipotency of hAT-MSCs was confirmed by differentiation into adipogenic, osteogenic and chondrogenic lineages. hAT-MSCs were irradiated with Er:YAG laser (wavelength 2940 nm, frequency 5, 10 Hz, doses: 0.1–1.2 J/cm²) for 2 s and 4 s and diode laser (wavelength 635 nm and doses: 1–8 J/cm²) for 5, 10, 20, 30 and 40 s. Cell viability was analysed 24 h after the exposure using MTT assay.

Results

Growth stimulation of hAT-MSCs after 5 Hz Er:YAG laser exposure, 0.1 J/cm² dose for 4 s and 0.3 J/cm² dose for 4 s was shown in comparison with the control group. Significant growth stimulation of hAT-MSCs after diode laser irradiation in doses of 1–4 J/cm² was demonstrated compared to the control group.

Conclusions

The presented results indicate that both lasers, Er:YAG and diode can be used to stimulate stem/stromal cell growth in vitro. The biostimulative effect of laser therapy on stromal cells may be used in the future in aesthetic dermatology in combined laser and cell therapy.