三种剂量630nm弱激光对Wistar大鼠背部皮肤开放型创伤愈合的作用观察

目的:从创伤面积收缩率和组织病理学角度观察630nm连续输出型弱激光,在功率密度一定(10mW/cm 2)时,每日创面照射剂量分别为1.2J/cm 2、2.4J/cm 2和3.6J/cm 2对Wistar大鼠背部皮肤开放型创伤愈合的影响.方法:用手术剪在每只Wistar大鼠背部造四个圆形、全层皮肤切除的创口,按照完全随机设计,将同一只大鼠背部的四个创口划分到空白对照组和三个不同剂量照射组,造创半小时后照射,连续照7天;再将大鼠随机分为1~6组,依次在造创后的第12、24、48、72、120和168小时处死取材,进行HE染色,光镜下评价;对第5、6组的样本增加马松(Masson)特染,光镜下评价;并对第6组在每次照射前用无菌薄膜沿边缘描记一次创面,采用ImageJ图像处理软件计算创口面积,对数据进行方差分析.结果:创伤面积的方差分析结果表明,空白对照组与各照射组之间不存在统计学差异;而组织病理学观察结果表明,弱激光照射组较空白对照组有以下特点:炎性期持续时间短,肉芽组织出现早,在同一时期,肉芽组织成熟、胶原数量多且其中成熟胶原所占比重大、表皮新生速度快,并且,这种优势随着所用剂量的增加而更加明显.结论:功率密度为10mW/cm 2,剂量分别为1.2J/cm 2、2.4J/cm 2和3.6J/cm 2的630nm弱激光照射能够产生创伤部位局部效应,促进Wistar大鼠背部皮肤开放型创伤的愈合过程,并且随着剂量的增加,创伤愈合效果越好.     

弱激光促进糖尿病大鼠模型皮肤创伤愈合的实验研究

探讨弱激光对糖尿病大鼠皮肤创伤愈合过程的影响.32只糖尿病大鼠背部皮肤全层创口随机分为4组,分别为:功率密度5、10和15 mW/cm2的630nm半导体激光照射组及空白对照组.弱激光照射能明显加速创面收缩,减轻炎症反应,加快成纤维细胞的增殖和胶原蛋白的合成,促进上皮细胞和毛细血管再生,促进创伤愈合.其中功率密度15 mW/cm2的弱激光治疗组疗效最为明显.实验前后各组大鼠血糖水平均无显著差异.弱激光对糖尿病大鼠皮肤创伤愈合确实存在促进作用,且疗效存在光学参数依赖性.     

1318.8 nm/1338 nm同时振荡双波长Nd:YAG激光器

通过双波长激光理论计算激光振荡的阈值条件,抑制强线1064nm振荡,成功实现了1318.8nm/1338nm NdYAG同时双波长激光准连续输出,当抽运功率为2015W时,双波长激光总平均输出功率为101W,电-光转换效率为5.01%,斜率效率为7.05%,激光输出功率不稳定度≤±5%.双波长激光中心波长分别在1318.8nm、1338.2nm处,谱线宽度(FWHM)分别为0.407nm、0.376nm.     

1318.8nm /1338nm同时振荡双波长Nd∶YAG激光器

通过双波长激光理论计算激光振荡的阈值条件,抑制强线1064nm振荡,成功实现了 1318. 8nm /1338nm Nd∶YAG同时双波长激光准连续输出,当抽运功率为2015W时,双波长激光总平均输出功率为101W,电2光转换效率为5. 01% ,斜率效率为7. 05% ,激光输出功率不稳定度≤ ±5%。双波长激光中心波长分别在1318. 8nm、1338. 2nm处,谱线宽度( FWHM)分别为0. 407nm、0. 376nm。     

1318.8nm /1338nm同时振荡双波长Nd∶YAG激光器

通过双波长激光理论计算激光振荡的阈值条件,抑制强线 1064nm振荡,成功实现了1318. 8nm/1338nmNd∶YAG同时双波长激光准连续输出,当抽运功率为 2015W时,双波长激光总平均输出功率为 101W,电 光转换效率为 5. 01%,斜率效率为 7. 05%,激光输出功率不稳定度≤±5%。双波长激光中心波长分别在 1318. 8nm、1338. 2nm处,谱线宽度 (FWHM)分别为 0. 407nm、0. 376nm。     

784.9 nm和808 nm激光二极管抽运Tm/Ho键合激光器

研究了室温下784.9 nm和808 nm的激光二极管(LD)抽运Tm/Ho键合激光器,增益介质是由Tm:YAG和Ho:YAG晶体扩散键合而成的Tm/Ho:YAG键合晶体;对两种LD抽运源下的Ho激光性能,包括输出功率、光束质量、输出波长进行对比。低抽运吸收功率下,采用808 nm LD抽运的激光器效率稍低于784.9 nm LD,验证了基于Tm/Ho键合增益介质这一新型激光实现机制在抽运波长选择上的宽可适用性。在784.9 nm的抽运波长下,实现了室温下最高1.89 W的激光输出,光-光转换效率为26.4%,斜率效率为40.78%;在常规808 nm LD的抽运下,实现了室温下最高1.74 W的激光输出,光-光转换效率为24.4%,斜率效率为40.31%。两种抽运条件下,最高输出功率所对应的激光波长均在2122 nm附近。     

双波长585nm/1064nm Nd:YAG激光治疗面部皱纹的效果与安全性

为观察双波长585nm/〖J P 〗1064 nm Nd:YAG激光治疗面部皱纹的疗效与安全性,对42例面部皱纹女性患者采用 双波长585nm/1064nm Nd:YAG 激光 治疗,每4周治疗1次,共5次。通过医师主观评价和VISIA皮肤分析仪对有效性和安全性进行 综合评定。结果表明, 治疗后,所有病例均有改善,临床有效率为92.86％,患者面部皱纹 及毛孔的VISIA值明 显下降,与治疗前相比,差异有统计学意义(P＜0.001)。这表明,Nd:YAG激光用于 面部皱纹的治疗疗效显著,安全性 高。     

波长锁定878.6nm激光二极管抽运Nd:YVO_4 1064nm激光器

报道了一种由波长锁定878.6nm半导体激光器抽运Nd:YVO4晶体的1064nm激光器,当晶体吸收7.41W的抽运功率时获得了5.75W的1064nm激光输出,相对于吸收功率的斜率效率为80.2%,光光转换率为77.6%,并且对波长锁定878.6nm,非波长锁定的808nm,878.6nm抽运的激光器的温度特性进行了研究,结果表明利用波长锁定878.6nm作为抽运源的激光器在10℃~40℃的温度变化范围内具有很好的输出稳定性。     

两种波长低强度激光照射巨噬细胞的生物效应比较

目的研究相同照射条件下的低强度532nm和650nm激光照射小鼠腹腔巨噬细胞的生物效应.方法用相同功率和照射时间的532nm和650nm激光辐照小鼠腹腔巨噬细胞,采用中性红吞噬实验测定巨噬细胞的吞噬能力.结果相同功率的两种波长激光在适当的照射时间下巨噬细胞的吞噬能力有显著性增强,巨噬细胞吞噬能力随照射时间的变化规律相似.结论相同照射条件下,低强度532nm和650nm激光照射巨噬细胞的生物效应相似,都可以激活小鼠腹腔巨噬细胞,增强其免疫活性,只是532nm激光的效应略强一些.     

端面泵浦Nd:YAG连续输出1052nm波长激光器

设计了一个简单紧凑的1052nm波长激光器.首次利用激光二极管（LD）端面泵浦Nd：YAG晶体,使用镀有高度选择性介质膜的反射镜产生该波段的激光.激光阈值为0.3W,当808nm波长泵浦光功率达到18W时产生了3.5W的1052nm波长激光输出.光-光转换效率为20%,输出激光功率波动不超过3%.     

He-Ne激光对愈合延迟创面修复的促进作用

目的 :观察He -Ne激光对整形手术愈合延迟创面的修复作用及可能发生的不良反应。方法 :选择整形术后创面愈合延迟患者 42例为受试对象 ,A组 ( 2 2例 )为治疗组 ,用He -Ne激光照射联合常规换药方法处理 ,B组 ( 2 0例 )为对照组 ,单纯采用常规换药方法处理 (观察激光对坏死或感染创面有无促进愈合作用及是否可减少再手术植皮率 ,并观察其不良反应 )。结果 :A组患者创面 3周内愈合率为 86 .82 % ,B组患者创面 3周内愈合率为 5 5 % ;A组患者再手术植皮率明显低于B组。 (P <0 .0 5 )A组创面分泌物及创周炎明显轻于B组 ;两组患者创面均未发现明显不良反应。结论 :He -Ne激光可促进整形术后愈合延迟创面愈合 ,缩短愈合时间 ,减少再手术植皮率 ,无明显不良反应     

Rapid Fabrication of Self‐Healing,Conductive, and Injectable Gel as Dressings for Healing Wounds in Stretchable Parts of the Body

Skin wounds on stretchable parts of the body including the elbows, knees, wrists, and nape usually undergo delayed and poor healing due to the interference of their frequent motion. Ordinary dressings that are not flexible enough face difficulty to promote wound healing due to the mismatching between the mechanics of the dressing materials and the wounds. In this study, an injectable, biocompatible, self‐healable, and conductive material poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonate)/guar slime (PPGS) is developed for healing wounds with various kinds of movements. As a proof‐of‐principle assay, the healing effect of PPGS is explored on a skin wound model on the nape of rats that often experiences frequent movements. PPGS, which can be prepared within 1 min, successfully accelerates the healing of the wounds. The results suggest that PPGS has great potential in the fields of tissue engineering and biomedicine.     

大鼠两种实验性创伤对He－Ne激光的反射特性

本实验用Ｈｅ－Ｎｅ激光照射大鼠开放性伤口、烫伤促进其愈合，同时测定了愈合过程中创面对Ｈｅ—Ｎｅ激光的漫反射比。结果表明；（１）整个愈合过程中，两种伤口的漫反射比均随时间发生变化，其变化趋势大体相同。（２）两种伤口的漫反射比不同。（３）愈合过程中两种伤口漫反射比变化的最大幅度不同。（４）漫反射比变化最大幅度的相对值相同，与伤口性质无关。研究结果具有临床意义。     

Multivalent Glycosheets for Double Light–Driven Therapy of Multidrug‐Resistant Bacteria on Wounds

With the evergrowing threat posed by multidrug resistance of bacteria, the development of effective antibacterial agents remains a global challenge. Infection with multidrug‐resistant bacteria in hospitals significantly impairs the healing of wounds caused by deep‐burn injuries or diabetic foot ulceration, leading to a high mortality rate among these patients. A multivalent glycosheet for the double light–driven therapy against multidrug‐resistant Pseudomonas aeruginosa (P. aeruginosa) infection on wounds is developed here. Galactose‐ and fucose‐based ligands are self‐assembled to form a glyco‐layer on the surface of thin‐layer molybdenum disulfide, producing the glycosheets capable of selectively localizing P. aeruginosa through multivalent carbohydrate–lectin interactions. The glycosheets loaded with antibiotics have proven applicable for: 1) near‐infrared‐light driven, in situ thermal release of antibiotics, increasing bacterial membrane permeability, and 2) white light–driven reactive‐oxygen‐species production to more thoroughly kill the bacteria. The targetability, together with the light sensibility, of the glycosheets enables a highly effective and optically controlled therapeutic regime for the healing of wounds infected by multidrug‐resistant as well as clinically isolated P. aeruginosa.     

Nanofiber Aerogels with Precision Macrochannels and LL-37-Mimic Peptides Synergistically Promote Diabetic Wound Healing

Fast healing of diabetic wounds remains a major clinical challenge. Herein, this study reports a strategy to combine nanofiber aerogels containing precision macrochannels and the LL-37-mimic peptide W379 for rapid diabetic wound healing. Nanofiber aerogels consisting of poly(glycolide-co-lactide) (PGLA 90:10)/gelatin and poly-p-dioxanone (PDO)/gelatin short electrospun fiber segments are prepared by partially anisotropic freeze-drying, cross-linking, and sacrificial templating with 3D printed meshes, exhibiting nanofibrous architecture and precision micro-/macrochannels. Like human cathelicidin LL-37, W379 peptide at a concentration of 3 µg mL⁻¹ enhances the migration and proliferation of keratinocytes and dermal fibroblasts in a cell scratch assay and a proliferation assay. In vivo studies show that nanofiber aerogels with precision macrochannels can greatly promote cell penetration compared to aerogels without macrochannels. Relative to control and aerogels with and without macrochannels, adding W379 peptides to aerogels with precision macrochannels shows the best efficacy in healing diabetic wounds in mice in terms of cell infiltration, neovascularization, and re-epithelialization. The fast re-epithelization could be due to the upregulation of phospho-extracellular signal-regulated kinase (p38 mitogen-activated protein kinase) after treatment with W379. Together, the approach developed in this study could be promising for the treatment of diabetic wounds and other chronic wounds.     

Charge-Driven Self-Assembled Microspheres Hydrogel Scaffolds for Combined Drug Delivery and Photothermal Therapy of Diabetic Wounds

The treatment of diabetic wound remains a big clinical challenge. Hydrogel that can provide physical barrier and humidity displays amazing potentials for managing the diabetic wounds healing. Herein, a new charge-driven self-assembled microsphere hydrogel scaffold (SMHS) is reported based on an electric charge interaction, by combining use of black phosphorus (BP)-contained chitosan methacryloyl (CS) microspheres with positive charge and basic fibroblast growth factor-contained hyaluronic acid methacryloyl (HA) microspheres with negative charge. The weak charge attraction among microspheres gives the SMHS the injectable characteristic. Due to the existence of BP, near-infrared (NIR) irradiation has obvious effects on the degradation and drug release behaviors of SMHS. Significantly, SMHS that combines the short-term physical (photothermal) intervention and long-term chemical (drug release) intervention may be promising in spatio-temporal regulation of regenerative microenvironment. SMHS with NIR irradiation (SMHS+NIR) can promote cell proliferation, cell migration, angiogenesis and macrophage polarization. Moreover, in diabetic rat skin wounds, SMHS+NIR significantly accelerates the wound healing process by simultaneously inhibiting the inflammatory response, promoting angiogenesis and tissues remodeling. The outcome of this research not only provides a biomaterial for diabetic wounds healing, but also demonstrates a new strategy for designing novel hydrogel-based biomaterials which have the free editing and combination functions.     

Microgel Assembly Powder Improves Acute Hemostasis,Antibacterial, and Wound Healing via In Situ Co-Assembly of Erythrocyte and Microgel

Rapid and effective hemostasis on irregular-shaped non-compressible bleeding wounds is still one of the key challenges in clinical practice. Herein, a novel multi-functional microgel assembly powder (MAP) composed of oxidized dextran/methacrylate gelatin (ODex/GelMA) microgel powder and long-chain alkyl quaternized chitosan (LQCS) crosslinker powder is reported for acute hemostasis, antibacterial, and wound healing. When MAP is applied onto bleeding wounds, porous ODex/GelMA microgel powder immediately absorbs massive liquid in blood whilst LQCS induces in situ co-assembly of erythrocytes and microgels. In other words, MAP combines the merits of hemostatic powders and hemostatic hydrogels, that is, the excellent hemostasis performance of MAP is originated from not only the high fluid uptake ratio/rate that causes the aggregation of coagulation factors and erythrocytes, but also the formation of erythrocytes-involved hydrogel-like microgel assembly that dramatically improves the mechanical strength, tissue adhesion and wound sealing performance in blood compared with those in PBS. In addition, MAP also exhibits excellent antibacterial ability, and promotes the wound healing in bacterial-infected full-thickness skin wounds. The fantastic features of MAP including low cost, easy synthesis and usage, excellent hemostasis on irregular-shaped, non-compressible bleeding wounds, outstanding antibacterial and wound healing, good cytocompatibility, make it a promising hemostatic material and wound dressing.     

A Textile Dressing for Temporal and Dosage Controlled Drug Delivery

Chronic wounds do not heal in an orderly fashion in part due to the lack of timely release of biological factors essential for healing. Topical administration of various therapeutic factors at different stages is shown to enhance the healing rate of chronic wounds. Developing a wound dressing that can deliver biomolecules with a predetermined spatial and temporal pattern would be beneficial for effective treatment of chronic wounds. Here, an actively controlled wound dressing is fabricated using composite fibers with a core electrical heater covered by a layer of hydrogel containing thermoresponsive drug carriers. The fibers are loaded with different drugs and biological factors and are then assembled using textile processes to create a flexible and wearable wound dressing. These fibers can be individually addressed to enable on‐demand release of different drugs with a controlled temporal profile. Here, the effectiveness of the engineered dressing for on‐demand release of antibiotics and vascular endothelial growth factor (VEGF) is demonstrated for eliminating bacterial infection and inducing angiogenesis in vitro. The effectiveness of the VEGF release on improving healing rate is also demonstrated in a murine model of diabetic wounds.     

Optical properties of wounds: diabetic versus healthy tissue

Diffuse photon density wave (DPDW) methodology at Near Infrared frequencies has been used to calculate absorption and scattering from wounds of healthy and diabetic rats. The diffusion equation for semi-infinite media is being used for calculating the absorption and scattering coefficients based on measurements of phase and amplitude with a frequency domain device. Differences observed during the course of healing in the two populations can be correlated to the delayed healing observed in diabetics. These results are encouraging and further work will focus on the implementation of this device to the clinical setting as a monitoring tool in chronic diabetic wounds.     

Ultrafast Self-Gelling and Wet Adhesive Powder for Acute Hemostasis and Wound Healing

Achieving rapid and effective hemostasis on irregularly shaped, non-compressible visceral, and high-pressure arterial bleeding wounds remains a critical clinical challenge. Herein, an ultrafast self-gelling and wet adhesive polyethyleneimine/polyacrylic acid/quaternized chitosan (PEI/PAA/QCS) powder is reported as the hemostatic material and wound dressing. PEI/PAA/QCS powder deposited on bleeding wounds can rapidly absorb a large amount of blood to concentrate coagulation factors. Meanwhile, the powder can form an adhesive hydrogel in situ within 4 s upon hydration to form a pressure-resistant physical barrier. Furthermore, PEI/PAA/QCS hydrogels can aggregate blood cells and platelets to enhance hemostasis. Depositing PEI/PAA/QCS powder on various bleeding wounds, including at the liver and heart, high-pressure femoral artery and tail vein of rats, arrests the bleeding around 10 s with no rebleeding after ten minutes. Excellent hemostasis of PEI/PAA/QCS powder is further demonstrated against massive hemorrhage in porcine spleen and liver in vivo, which are non-compressible organs with abundant blood supply. In addition, the powder can be used as a wound dressing to promote the healing of the full-thickness skin wounds. The advantages of PEI/PAA/QCS powder including rapid and effective hemostasis, effective wound healing, easy usage, low cost, and adaptability to fit complex target sites make it a promising biomaterial for surgical applications.