Serial Laser Research Articles

A six degrees of freedom femtosecond laser system for fabrication of small-scale mechanical property specimens.

We present the details of a novel ultra-short pulsed laser machining workstation that has been employed for high-throughput laser machining of small-scale mechanical property specimens. This system employs a six degrees of freedom hexapod positioning stage capable of macroscopic movements at high positional accuracy. We developed a methodology that uses quantitative image analysis to measure key parameters required to minimize the hexapod positioning and rotational error. Application of this system to laser machining of small-scale 316L stainless steel tensile specimens and ultra-high molecular weight polyethylene compressive specimens using eucentric tilt and rotation about the specimen axis will be shown, where serial laser milling at a specimen tilt angle of 10° was used to effectively eliminate any taper in the sample cross section that is typically found in laser machining.

Corneal reinnervation in patients with severe neurotrophic keratopathy secondary to herpes zoster ophthalmicus after treatment with autologous serum tear drops.

To study potential corneal reinnervation and recovery of corneal sensation in patients with severe neurotrophic keratopathy (NK) secondary to herpes zoster ophthalmicus (HZO) after treatment with topical autologous serum tears (AST). Four cases of HZO with severe NK were followed clinically and by serial laser in vivo confocal microscopy (IVCM, HRT3/RCM, Heidelberg Engineering) before and during treatment with 20% AST drops eight times a day. Two masked observers reviewed the IVCM images and assessed corneal nerve alterations. At baseline, all patients had complete loss of corneal sensation. In addition, IVCM showed complete lack of the subbasal corneal nerve plexus in all patients. All four patients were refractory to conventional therapies and were treated with AST drops. All patients demonstrated significant nerve regeneration by IVCM within 3-7 months of treatment. The total nerve density increased to a mean ± SEM of 10,085.88±2,542.74 μm/mm2 at the last follow up. Corneal sensation measured by Cochet-Bonnet esthesiometry improved to a mean ± SEM of 3.50±1.30 cm. Interestingly, 3 of 4 patients developed stromal keratitis with ulceration within weeks of corneal reinnervation, which was reversed by adding topical steroids. Autologous serum tears are effective in restoring corneal subbasal nerves and sensation in patients with severe NK secondary to HZO. However, this group of patients may require concurrent topical immunomodulation and antiviral therapy while on AST to prevent stromal keratitis.

Abstract 648: Divergent Roles For Endothelial Cell Marcks In Endothelial Cell Regeneration And Signaling After Arterial Injury And Ischemia

Cardiovascular interventions cause endothelial injury and trigger re-establishment of intact endothelium. After ischemia, endothelial signaling is essential for capillary angiogenesis as well as flow-mediated collateral artery enlargement to restore perfusion. We studied the role of the signaling protein MARCKS (myristoylated alanine-rich C kinase substrate) in the endothelial response to injury and ischemia-induced angiogenesis. Methods: Targeted deletion of MARCKS in endothelial cells was done with Cadherin 5-driven Cre/Lox recombination and confirmed with immunohistochemistry. All controls were Cre(-) littermates. Re-endothelialization after femoral artery wire injury was measured by arterial area quantitation after Evan’s Blue exclusion. After femoral artery ligation, limb blood flow was determined by serial laser Doppler scanning, and angiogenesis by counting CD31-positive cells in the gastrocnemius muscle on day 28. Results: Endothelial cell-specific deletion of MARCKS was confirmed in Cre (+) animals. Deletion of MARCKS did not affect endothelial regeneration on post operative day 6 after denuding femoral wire injury (68.2% versus 68.7% recovery, n=5-6, p>.05). Ischemia-induced capillary angiogenesis was not affected by deletion of MARCKS (Capillary Count, Cre(+): 602 versus Cre(-): 511, n=6, p>.05), however animals lacking endothelial MARCKS had worsened limb perfusion on days 1, 3, 7 and 21 after ischemia (ABI Range Cre(+) versus Cre(-): 0.04-0.22 versus 0.07-0.41, respectively, n=6-9, p<.05). Conclusions: These studies demonstrate distinct and divergent roles for MARCKS in the endothelial cell response to injury and ischemia. MARCKS is not essential for endothelial regeneration after denuding large vessel injury, or for capillary angiogenesis induced by ischemia. Surprisingly, endothelial MARCKS appears to be a novel endogenous promotor of ischemia-induced limb revascularization. This suggests that endothelial cell MARCKS promotes flow-mediated endothelial cell signaling essential for ischemia-induced arterial enlargement. MARCKS activity could be a possible therapeutic target to enhance collateral artery formation in limb ischemia.

Automating serial laser processing with cobots

AbstractNo more limitations due to the character set or material properties: laser markers can label a wide variety of workpieces of different materials, quickly and durably.

Dual Function of a in vivo Albumin-Labeling Tracer for Assessment of Blood Perfusion and Vascular Permeability in Peripheral Arterial Disease by PET.

BackgroundPeripheral arterial disease (PAD) leads to tissue ischemia in the extremities. Enhanced vascular permeability plays a critical role in targeted delivery of drugs for effective therapeutic angiogenesis and resultant blood perfusion recovery. However, optimal tracers for evaluating this process in PAD patients are lacking. At this time, we employed a novel in vivo albumin-labeling tracer of dual function, termed as 18F-NEB, to assess blood perfusion as well as vascular permeability by positron emission tomography (PET).Methods and ResultsAfter successful establishment of mouse hindlimb ischemia (HI) model, static PET imaging was performed 15 min and 2 h post injection (p.i.) of 18F-NEB at 1, 3, 5, 7, 10 and 14 days post-surgery respectively. Gradual recovery of blood supply was detected by PET scan 15 min p.i. and collaborated by serial Laser Doppler. In addition, the highest vascular permeability observed by high local uptake of 18F-NEB at 2 h p.i. was consistent with histological examinations. Furthermore, we quantitatively evaluated the effect of vascular endothelial growth factor (VEGF) stimulus on vascular permeability and blood perfusion by PET scan using 18F-NEB probe in HI model, which were also confirmed by immunohistological results.ConclusionThe application of 18F-NEB probe alone by PET can successfully achieve dual imaging of blood perfusion as well as vascular permeability at different time points p.i. and monitor their responses to therapy in PAD model. The simple labeling approach and multipurpose feature suggest the great promise of using this imaging probe in theranostic applications for treating ischemic disease.

Determination of Micropulse Modes with Targeted Damage to the Retinal Pigment Epithelium Using Computer Modeling for the Development of Selective Individual Micropulse Retinal Therapy

ABSTRACT Purpose When using a serial laser system for selective impact on the retinal pigment epithelium (RPE), there is a challenge to determine the optimal range of micropulse parameters which result in targeted damage to the RPE. This study proposes a computer model that has identified the optimal parameters to be applied. Methods This study was conducted on 18 patients who were diagnosed with acute central serous chorioretinopathy and transparent optical media, aged 35 to 46 years old, and type 2 and 3 on the Fitzpatrick scale. Testing of the micropulse mode was performed on the Navilas 577s laser system; 864 spots were analyzed in total. Considering the probability of damage visualization at different laser power, the computer simulation of tissue heating and protein denaturation was performed to determine the micropulse modes which resulted in selective damage to the RPE. Results The computer model parameter ΔE = 3.34 × 105 J/mol was determined from fitting the model predictions to the autofluorescence test results. The micropulse modes with a micropulse duration of 50–100 µs, duty cycle 2.4–4.8%, 10 ms-pulse envelope (5 micropulses), and spot diameter of 100 µm have efficiency and selectivity above 67% and correspond to the optimal therapeutic window for targeted RPE damage at a certain power. Increasing the micropulse duration, number of micropulses, and duty cycle leads to a decrease in the selective effect on the RPE and higher damage to adjacent tissues. Conclusion The concepts of efficiency and selectivity have been introduced to quantify the amount of damage caused. The optimal range of micropulse parameters which result in effective and selective damage on the RPE has been determined for the Navilas 577s laser system. The proposed method can be used for any other serial laser system. A comparison of the different micropulse modes, as well as the CW modes, has been performed.

Use of 532 nm Potassium Titanyl Phosphate Laser on Vocal Fold Scars Under Topical Anesthesia: A Pilot Study

This pilot study aims to evaluate the efficacy of 532 nm potassium titanyl phosphate (KTP) laser under topical anesthesia in patients with vocal fold scars. A series of 18 patients with vocal fold scars of varying degrees were treated. The KTP laser was used under local anesthesia in the outpatient clinic. It was set to deliver 6 W of power using a continuous output mode. Close-to-contact mode was used for laser irradiation, and contact mode was used for ablation and excision of the lesions. Some of the patients received laser scar ablation on both vocal folds; the scarred vocal fold on one side and the hypertrophic vocal fold on the other. Parameters include glottic closure, amplitude, and mucosal wave pattern were measured using laryngeal stroboscopic examination. Aerodynamic and voice evaluations were carried out using maximum phonation time (MPT), jitter, shimmer, Voice Handicap Index questionnaire (VHI-30), and GRBAS scale. In total, 21 surgeries were performed on 18 patients. Glottic closure, amplitude, and mucosal wave pattern showed improvement 2 months postoperatively (P < .05). There was significant improvement in the postoperative scores for VHI-30, VHI-emotional sub-scale, VHI-physical sub-scale, and GRBAS (P < .05). There was no significant difference in the MPT and VHI-functional sub-scale before and after the operation (P > .05). Re-adhesion of the anterior commissure was observed in 2 patients with Type III scars. The 532 nm KTP laser is an effective tool for the treatment of vocal fold scars. Further research is required to determine if serial laser applications could improve outcomes for this challenging condition. Level IV.

Heat shock protein A12B gene therapy improves perfusion, promotes neovascularization, and decreases fibrosis in a murine model of hind limb ischemia

BackgroundHeat shock protein A12B expressed in endothelial cells is important and required for angiogenesis to form functional vessels in ischemic tissue. We have previously shown the cardioprotective effects of heat shock protein A12B overexpression in a rat model of diabetic myocardial infarction. In this study, we aim to explore the role of heat shock protein A12B in a surgically-induced murine hind-limb ischemia model. Materials and MethodsAdult 8- to 12-week-old C57BL/6J mice were divided into 2 groups: treated with Adeno.LacZ (control group) and with Adeno.HSPA12B (experimental group) and, with both groups subjected to right femoral artery ligation. Immediately after surgery, mice in both groups received either Adeno.HSPA12B or Adeno.LacZ (1 × 109 plaque forming units) in both the semimembranosus and gastrocnemius muscles of the right limb. The left limb served as the internal control. Both groups underwent serial laser Doppler imaging preoperatively, and again postoperatively until 28 days. Immunohistochemical analysis was performed 3 and 28 days post-surgery. ResultsMice in the Adeno.HSPA12B gene therapy group showed improved motor function and a significantly higher blood perfusion ratio on postoperative days 21 and 28, along with better motor function. Immunohistochemical analysis showed increased expression of vascular endothelial growth factor, thioredoxin-1, heme oxygenase, and hypoxia-inducible factor 1α, along with a decreased expression of A-kinase-anchoring protein 12 and thioredoxin-interacting protein levels. The Adeno.HSPA12B-treated group also showed increased capillary and arteriolar density and an increased capillary-myocyte ratio, along with reduced fibrosis compared to the Adeno.LacZ group. ConclusionOur study demonstrates that targeted Adeno.HSPA12B gene delivery into ischemic muscle enhances perfusion and angiogenic protein expression. This molecule shows promise for the management of peripheral vascular disease as a potential target for clinical trials and subsequent drug therapy.

Morphology of Stephanella hina (Bryozoa, Phylactolaemata): common phylactolaemate and unexpected, unique characters

Stephanella hina is a little studied freshwater bryozoan belonging to Phylactolaemata. It is currently the only representative of the family Stephanellidae, which in most reconstructions is early branching, sometimes even sister group to the remaining phylactolaemate families. The morphological and histological details of this species are entirely unknown. Consequently, the main aim of this study was to conduct a detailed morphological analysis of S. hina using histological serial sections, 3D reconstruction, immunocytochemical staining and confocal laser scanning microscopy techniques. The general morphology is reminiscent of other phylactolaemates; however, there are several, probably apomorphic, details characteristic of S. hina. The most evident difference lies in the lophophoral base, where the ganglionic horns/extensions do not follow the traverse of the lophophoral arms but bend medially inwards towards the mouth opening. Likewise, the paired forked canal does not fuse medially in the lophophoral concavity as found in all other phylactolaemates. Additional smaller differences are also found in the neuro-muscular system: the rooting of the tentacle muscle is less complex than in other phylactolaemates, the funiculus lacks longitudinal muscles, the caecum has smooth muscle fibres, latero-abfrontal tentacle nerves are not detected and the medio-frontal nerves mostly emerge directly from the circum-oral nerve ring. In the apertural area, several neurite bundles extend into the vestibular wall and probably innervate neurosecretory cells surrounding the orifice. These morphological characteristics support the distinct placement of this species in a separate family. Whether these characteristics are apomorphic or possibly shared with other phylactolaemates will require the study of the early branching Lophopodidae, which remains one of the least studied taxa to date.

Cathepsin K Deficiency Impaired Ischemia-Induced Neovascularization in Aged Mice.

Background Aging is a major risk factor for cardiovascular disease. Cysteine protease cathepsin K (CatK) has been implicated in the process of angiogenesis, but the exact roles of individual CatK in vessel formation during aging are poorly understood. Methods and Results To study the putative role of CatK in ischemia-induced angiogenesis, we applied a hindlimb ischemia model to aged wild-type (CatK+/+) and CatK-deficient (CatK−/−) mice. A serial laser Doppler blood-flow analysis revealed that the recovery of the ischemic/normal blood-flow ratio in the aged CatK−/−mice was impaired throughout the follow-up period. On postoperative day 14, CatK deficiency had also impaired capillary formation. CatK deficiency reduced the levels of cleaved Notch1, phospho-Akt, and/or vascular endothelial growth factor (VEGF) proteins in the ischemic muscles and bone marrow-derived c-Kit+ cells. A flow cytometry analysis revealed that CatK deficiency reduced the numbers of endothelial progenitor cell (EPC)-like CD31+/c-Kit+ cells in the peripheral blood as well as the ischemic vasculature. In vitro experiments, CatK−/− impaired bone-derived c-Kit+ cellular functions (migration, invasion, proliferation, and tubulogenesis) in aged mice. Our findings demonstrated that aging impaired the ischemia-induced angiogenesis associated with the reductions of the production and mobilization of CD31+/c-Kit+ cells in mice. Conclusions These findings established that the impairment of ischemia-induced neovascularization in aged CatK−/− mice is due, at least in part, to the reduction of EPC mobilization and the homing of the cells into vasculature that is associated with the impairment of Notch1 signaling activation at advanced ages.

Metamorphic barcodes based on lithographically defined microdots incorporating nanoparticles of phase change materials

Printed barcode lacks distributability as each barcode associated with sample cannot be divided when multiple copies of the same barcode are needed for forensic analysis. This article reports a metamorphic barcode with desired distributability to label objects (liquids or solids) in a covert and high-fidelity manner using polymer microdots containing a panel of phase change nanoparticles (low melting point metal or alloy). The microdots can be made with photolithography at large quantity or serial laser fabrication and have unique serialization numbers based on the melting characteristics of nanoparticles. The microdots can be distributed evenly in liquid or attached on various location of an object and decoded with differential scanning calorimeter. Incorporation of magnetic nanoparticles allows facile collection of polymer microdots with a magnet. The microdots are non-toxic and stable over one year without losing coding information and have higher large labeling capacity than other covert barcode systems.

Ultrafast multi-focus 3-D nano-fabrication based on two-photon polymerization

Two-photon polymerization (TPP) is the most precise 3-D printing process that has been used to create many complex structures for advanced photonic and nanoscale applications. However, to date the technology still remains a laboratory tool due to its high operation cost and limited fabrication rate, i.e., serial laser scanning process. Here we present a revolutionary laser nanofabrication process based on TPP and an ultrafast random-access digital micromirror device (DMD) scanner. By exploiting binary holography, the DMD scanner can simultaneously generate and individually control one to tens of laser foci for parallel nanofabrication at 22.7 kHz. Complex 3-D trusses and woodpile structures have been fabricated via single or multi-focus processes, showing a resolution of ~500 nm. The nanofabrication system may be used for largescale nano-prototyping or creation of complex structures, e.g., overhanging structures, that cannot be easily fabricated via conventional raster-scanning-based systems, bringing significant impact to the world of nanomanufacturing.

Fetoscopic Laser Coagulation in Twin-Twin Transfusion Syndrome: Case Series

Twin-to-twin transfusion syndrome is a fatal complication and twins with monochorionic/diamniotic placentas are affected due to placental vascular anastomoses, producing volume transfer of blood from one twin to the other. The donor twin becomes hypovolemic with oligohydramnios and the recipient becomes hypervolemic with polyhydramnios. Twin-to-twin transfusion syndrome is associated with increased perinatal morbidity and mortality and expresses longstanding health hazards. Serial amnioreduction and fetoscopic laser photocoagulation of the vascular anastomoses are the main therapeutic approaches for twin-to-twin transfusion syndrome. Higher survival rates after fetoscopic laser ablation of the anastomotic vessels in comparison to serial amnioreduction have been reported in multicenter randomized clinical trials. We report the fetoscopic laser coagulation of three twin-to-twin transfusion syndrome cases at Ankara Dr. Zekai Tahir Burak Health Practice Research Center, Perinatology Clinics.

MicroRNA-146a Regulates Perfusion Recovery in Response to Arterial Occlusion via Arteriogenesis.

The growth of endogenous collateral arteries that bypass arterial occlusion(s), or arteriogenesis, is a fundamental shear stress-induced adaptation with implications for treating peripheral arterial disease. MicroRNAs (miRs) are key regulators of gene expression in response to injury and have strong therapeutic potential. In a previous study, we identified miR-146a as a candidate regulator of vascular remodeling. Here, we tested whether miR-146a regulates in vitro angiogenic endothelial cell (EC) behaviors, as well as perfusion recovery, arteriogenesis, and angiogenesis in response to femoral arterial ligation (FAL) in vivo. We found miR-146a inhibition impaired EC tube formation and migration in vitro. Following FAL, Balb/c mice were treated with a single, intramuscular injection of anti-miR-146a or scramble locked nucleic acid (LNA) oligonucleotides directly into the non-ischemic gracilis muscles. Serial laser Doppler imaging demonstrated that anti-miR-146a treated mice exhibited significantly greater perfusion recovery (a 16% increase) compared mice treated with scramble LNA. Moreover, anti-miR-146a treated mice exhibited a 22% increase in collateral artery diameter compared to controls, while there was no significant effect on in vivo angiogenesis or muscle regeneration. Despite exerting no beneficial effects on angiogenesis, the inhibition of mechanosensitive miR-146a enhances perfusion recovery after FAL via enhanced arteriogenesis.

Re-assessing the enhanced permeability and retention effect in peripheral arterial disease using radiolabeled long circulating nanoparticles

As peripheral arterial disease (PAD) results in muscle ischemia and neovascularization, it has been claimed that nanoparticles can passively accumulate in ischemic tissues through the enhanced permeability and retention (EPR) effect. At this time, a quantitative evaluation of the passive targeting capabilities of nanoparticles has not been reported in PAD. Using a murine model of hindlimb ischemia, we quantitatively assessed the passive targeting capabilities of 64Cu-labeled PEGylated reduced graphene oxide – iron oxide nanoparticles (64Cu-RGO-IONP-PEG) through the EPR effect using positron emission tomography (PET) imaging. Serial laser Doppler imaging was performed to monitor changes in blood perfusion upon surgical induction of ischemia. Nanoparticle accumulation was assessed at 3, 10, and 17 days post-surgery and found to be highest at 3 days post-surgery, with the ischemic hindlimb displaying an accumulation of 14.7 ± 0.5% injected dose per gram (%ID/g). Accumulation of 64Cu-RGO-IONP-PEG was lowest at 17 days post-surgery, with the ischemic hindlimb displaying only 5.1 ± 0.5%ID/g. Furthermore, nanoparticle accumulation was confirmed by photoacoustic imaging (PA). The combination of PET and serial Doppler imaging showed that nanoparticle accumulation in the ischemic hindlimb negatively correlated with blood perfusion. Thus, we quantitatively confirmed that 64Cu-RGO-IONP-PEG passively accumulated in ischemic tissue via the EPR effect, which is reduced as the perfusion normalizes. As 64Cu-RGO-IONP-PEG displayed substantial accumulation in the ischemic tissue, this nanoparticle platform may function as a future theranostic agent, providing both imaging and therapeutic applications.

Treatment of epidermal cysts with erbium: YAG laser fenestration: an alternative to surgical intervention.

Epidermal cysts, also called epidermal inclusion cysts or epidermoid cysts, are firm, slowly growing benign tumors commonly seen in young or middle-aged adults. Surgical excision is the usual treatment for such lesions, with the inevitable sequelae of scarring, especially in the face, back, or sternal region. To evaluate the safety and feasibility of erbium:yttrium aluminum garnet laser fenestration of epidermal cysts for patients concerned about scarring, from January 2010 to July 2013, 25 patients with cosmetic concerns underwent serial laser treatment using the fenestration technique to decompress the cyst contents. Patient' satisfaction, scarring, and complications were assessed and analyzed. Twenty-three of the 25 patients obtained satisfactory cosmetic outcomes with rapid healing and minimal invasiveness. There was no evidence of scar formation, and no complications were observed at follow-up. Two patients received elective excision after reduction of the size of the cysts, and their scars were hidden well. Erbium:yttrium aluminum garnet laser fenestration might be a promising alternative to the surgical treatment of epidermal cysts, especially when the lesions are large or located in an aesthetically important area.

Therapeutic modalities of twin to twin transfusion syndrome

Twin to twin transfusion syndrome (TTTTS) accounts for approximately 10% of monochorionic twin pregnancies and, if left untreated, is associated with high morbidity and mortality rate. A net transfusion of blood flow from one fetus (donor twin) to the other (recipient twin) via placental vascular anastomoses has been supposed as the major etiology of TTTTS. The donor twin becomes hypovolemic and oliguria, oligohydramnios, and a variable degree of growth restriction develop, whereas the recipient twin manifests polyuria, polyhydramnios, and hydrops in response to hypervolemia. TTTTS can be treated by either serial amniocentesis or selective fetoscopic laser coagulation of the communicating vessels. The rationale for removal of large volumes of amniotic fluid is to prevent preterm delivery secondary to polyhydramnios and to improve fetal circulation by reducing pressure on the chorionic plate. On the other hand, the goal of laser therapy is to occlude vascular anastomoses, thereby interrupting intertwin blood exchange. Although laser treatment is associated with increased survival rate and reduced neurologic complications, compared with amnioreduction, it requires highly specialized centers, whereas serial amniocentesis has the advantage of being performed worldwide. Therefore, the optimal treatment for pregnancies complicated with TTTTS is still controversial.

Development and Application of Mobile Digital Speckle Interferometer for Vibrometer Model Sample Honeycomb

The problems of the development of mobile digital speckle interferometer with a cw laser to obtain the vibration characteristics of the full-size structures in factory laboratories. Given the results of the use of the mobile testing interferometer for the study of vibration characteristics of model samples of honeycomb panels, different way to connect mobile plate frame with power-trim. Considering the cellular plate as a system with distributed parameters provides a method to determine its natural frequencies and mode shapes by acoustic excitation. The experimental results are compared with those of serial laser Doppler vibrometers.

基于布里渊放大串行激光组束研究进展

基于布里渊放大串行激光组束研究进展

Abstract 17955: Thereapeutic Angiogenesis Induced by Human Trx-1 Gene in Mice Hind Limb Ischemia Model: Preclinical Study for Treatment of Peripheral Artery Disease

Introduction: Peripheral artery disease affects 12-20% Americans over the age of 60. Thioredoxin-1 (Trx-1) is a class of small redox proteins. We have demonstrated earlier that Trx-1 reduces oxidative stress resulting in less inflammation and increased angiogenesis in cardiac muscle via heme oxygenase-1 (HO-1) and VEGF after myocardial infarction. In the current study, we evaluate the effect of Trx-1 on post-ischemic hindlimb recovery. Methods: Peripheral artery disease was mimicked using a hindlimb ischemia (HLI) model. Wild type (WT) and Trx-1 transgenic (Trx-1Tg/+) mice (8-12 weeks old) were subjected to femoral artery ligation. Following surgery, mice were observed for 5 weeks. Serial laser doppler images were obtained, and perfusion ratios between the ischemic and non-ischemic limbs were calculated at set time intervals. The perfusion ratios were compared between WT and Trx-1Tg/+ groups. Immunohistochemical analysis of the skeletal muscle was performed to quantify the extent of fibrosis, capillary and arteriolar density 35 days after surgery. In addition, another set of experiments was designed with Ad.Trx-1 gene therapy after femoral artery ligation to study the molecular mechanism of neovascularization with Trx-1. Results: The recovery of hind limb perfusion was significantly increased in Trx-1Tg/+ mice at day 7 (0.19 ± 0.03 vs. 0.36 ± 0.07 (n=12-9), day-21 (0.37 ± 0.05 vs. 0.62 ± 0.03 (n=12-9), and day 28 (0.40 ± 0.04 vs. 0.79 ± 0.04 (n=10-9); p&lt;0.05). Capillary density [1265 ± 87.8 vs. 762.4 ± 86.6 counts/mm2 ; (n=5); p&lt;0.05] and arteriolar density [36.2 ± 2.96 vs. 22± 1.33 counts/mm2 ; (n=5); p&lt;0.05] staining showed significant increase in Trx-1Tg/+ mice as compared to WT mice. Picrosirrus Red and immunofluorescence staining showed decreased fibrosis [8.3 ± 0.46 vs. 22.2 ± 1.04 (n=5); p&lt;0.0001] and increased HO-1 expression respectively in Trx-1Tg/+ mice group as compared to WT mice, respectively. Trx-1 gene therapy study also revealed by Western blot analysis, increased Trx-1 (4.2 fold) and HO-1 (8.2 fold) expression in Ad.Trx-1-HLI as compared to Ad.LacZ-HLI. Conclusions: Our results suggest that Trx-1 is a potential therapeutic agent to increase blood perfusion and angiogenesis for the treatment of critical limb ischemia patients.