scholarly journals Bioactive Nanofiber-based Conduits in a Peripheral Nerve Gap Management- an Animal Model Study.

2020 ◽  
Author(s):  
Dębski Tomasz ◽  
Ewa Kijeńska-Gawrońska ◽  
Aleksandra Zołocińska ◽  
Katarzyna Siennicka ◽  
Wiktor Paskal ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Peripheral Nerve ◽  
Nerve Fiber ◽  
Muscle Mass ◽  
Peripheral Nerve Regeneration ◽  
Nerve Reconstruction ◽  
Fiber Density ◽  
Lewis Rats ◽  
Group A ◽  
Group B

Abstract Background: Peripheral nerve injuries (PNI) are trauma with severe squeals for patients’ quality of life. Currently, the gold standard of nerve reconstruction relies on primary coaptation. However, in case of a nerve gap, a reconstructive material for bridging is needed. Nerve conduits are an increasingly popular solution alternative to autografts or processed nerved allografts. The aim of the study was to examine the efficiency of a novel bioactive nanofiber-based tubular scaffold made of poly (L-lactic acid)-co-poly(ϵ-caprolactone), collagen, polyaniline and enriched with adipose-derived stem cells (ASCs) as a nerve conduit in a rat model.Methods: Poly (L-lactic acid)-co-poly(ϵ-caprolactone) scaffold was optimized and enriched with collagen (COL) and polyaniline (PANI) to create final (P(LLA-CL)-COL-PANI), tubular-shaped scaffold, manufactured with electrospinning technology. Parallelly, adipose tissue from 10 Lewis rats was harvested for ASC culture. 28 inbred male Lewis rats were divided into four even groups. Each animal underwent sciatic nerve transection and excision of a 10 mm nerve trunk fragment. In group A, nerve gap remained untouched, in B excised trunk was rotated and used as an autograft, in C nerve stumps were secured with P(LLA-CL)-COL-PANI conduit. In the D group gap was reconstructed with P(LLA-CL)-COL-PANI conduit enriched with ASCs. After 6-months of observation rats were sacrificed. Gastrocnemius muscles (operated and non-operated side) and reconstructed sciatic nerves were harvested for analyses. Muscles were weighted and underwent histological analysis. Nerves were processed and stained immunohistochemically with NF-200 to be analyzed with dedicated software for nerve fiber count. Results: No signs of rejection or excessive fibrosis was noted. Muscle mass ratio was highest in group B (0.77±0.05), then in C (0.74±0,04) and D (0.67± 0.07). Group A showed advanced atrophy of the muscle, each intervention prevented muscle mass decrease (p<0.0001), however, ASC addition decreased efficiency vs autograft (p<0.05). Nerve fiber count revealed a superior effect in the nerve fiber density observed in the group with the use of conduit vs autograft (D vs B p<0.0001, C vs B p<0.001). ASC added to the conduit decreased perineurium hyperplasia.Conclusion: P(LLA-CL)-COL-PANI conduits with ASC showed promising results in managing nerve gap by decreasing muscle atrophy and providing a favorable environment for peripheral nerve regeneration.

scholarly journals Bioactive Nanofiber-Based Conduits in a Peripheral Nerve Gap Management—An Animal Model Study

2021 ◽  
Vol 22 (11) ◽  
pp. 5588
Author(s):  
Tomasz Dębski ◽  
Ewa Kijeńska-Gawrońska ◽  
Aleksandra Zołocińska ◽  
Katarzyna Siennicka ◽  
Anna Słysz ◽  
...  
Keyword(s):  
Nerve Fiber ◽  
Fiber Density ◽  
Lewis Rats ◽  
Model Study ◽  
Superior Effect ◽  
Animal Model Study ◽  
Group A ◽  
Group B ◽  
Gastrocnemius Muscles ◽  
Group D

The aim was to examine the efficiency of a scaffold made of poly (L-lactic acid)-co-poly(ϵ-caprolactone), collagen (COL), polyaniline (PANI), and enriched with adipose-derived stem cells (ASCs) as a nerve conduit in a rat model. P(LLA-CL)-COL-PANI scaffold was optimized and electrospun into a tubular-shaped structure. Adipose tissue from 10 Lewis rats was harvested for ASCs culture. A total of 28 inbred male Lewis rats underwent sciatic nerve transection and excision of a 10 mm nerve trunk fragment. In Group A, the nerve gap remained untouched; in Group B, an excised trunk was used as an autograft; in Group C, nerve stumps were secured with P(LLA-CL)-COL-PANI conduit; in Group D, P(LLA-CL)-COL-PANI conduit was enriched with ASCs. After 6 months of observation, rats were sacrificed. Gastrocnemius muscles and sciatic nerves were harvested for weight, histology analysis, and nerve fiber count analyses. Group A showed advanced atrophy of the muscle, and each intervention (B, C, D) prevented muscle mass decrease (p < 0.0001); however, ASCs addition decreased efficiency vs. autograft (p < 0.05). Nerve fiber count revealed a superior effect in the nerve fiber density observed in the groups with the use of conduit (D vs. B p < 0.0001, C vs. B p < 0.001). P(LLA-CL)-COL-PANI conduits with ASCs showed promising results in managing nerve gap by decreasing muscle atrophy.

scholarly journals A Comparative Study of Bioartificial Bone Tissue Poly-L-lactic Acid/Polycaprolactone and PLLA Scaffolds Applied in Bone Regeneration

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Weizong Weng ◽  
Shaojun Song ◽  
Liehu Cao ◽  
Xiao Chen ◽  
Yuanqi Cai ◽  
...  
Keyword(s):  
Lactic Acid ◽  
New Zealand ◽  
Bone Regeneration ◽  
Bone Tissue ◽  
Bone Defect ◽  
Mineral Density ◽  
Group A ◽  
Repair Bone Defect ◽  
Group B ◽  
New Zealand Rabbits

Bioartificial bone tissue engineering is an increasingly popular technique to repair bone defect caused by injury or disease. This study aimed to investigate the feasibility of PLLA/PCL (poly-L-lactic acid/polycaprolactone) by a comparison study of PLLA/PCL and PLLA scaffolds applied in bone regeneration. Thirty healthy mature New Zealand rabbits on which 15 mm distal ulna defect model had been established were selected and then were divided into three groups randomly: group A (repaired with PLLA scaffold), group B (repaired with PLLA/PCL scaffold), and group C (no scaffold) to evaluate the bone-remodeling ability of the implants. Micro-CT examination revealed the prime bone regeneration ability of group B in three groups. Bone mineral density of surgical site in group B was higher than group A but lower than group C. Meanwhile, the bone regeneration in both groups A and B proceeded with signs of inflammation for the initial fast degradation of scaffolds. As a whole, PLLA/PCL scaffoldsin vivoinitially degrade fast and were better suited to repair bone defect than PLLA in New Zealand rabbits. Furthermore, for the low mineral density of new bone and rapid degradation of the scaffolds, more researches were necessary to optimize the composite for bone regeneration.

scholarly journals Dentin tubule obturation of a bioglass-based dentin desensitizer under repeated exposure to lactid acid and brushing

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Andrea S. Manz ◽  
Thomas Attin ◽  
Beatrice Sener ◽  
Philipp Sahrmann
Keyword(s):  
Lactic Acid ◽  
Surface Composition ◽  
Superficial Layer ◽  
Sem Analysis ◽  
Collagen Fibers ◽  
Dentin Hypersensitivity ◽  
Edx Analysis ◽  
Dentin Tubule ◽  
Group A ◽  
Group B

Abstract Background Dentin hypersensitivity is a frequent finding especially in periodontitis patients. Conventional treatment aims for obstruction of dentin tubules by disabling liquid and osmotic fluctuation to and from the pulpal chamber. A novel bioglass-based desensitizer was shown to obstruct tubules and to resist periodic exposure to lactic acid. Whether this obstruction is resistant to brushing had not been tested so far. Accordingly, the present study aimed to assess dentin tubule obstruction after repeated acid exposure and brushing. Methods Sixty dentin discs were cleaned with 17% EDTA, mounted into a pulp fluid simulator and randomly divided into 3 groups: No surface treatment in Group A, Seal&Protect® in group B and DentinoCer in group C. Discs were exposed to 0.1 M non-saturated lactic acid thrice and standardized brushing twice a day for 12 days. At baseline and after 2, 4 and 12 d samples were removed from the setting and prepared for top-view SEM analysis to assess tubule obstruction using the Olley score. Discs were then vertically cut and the section surface morphologically assessed using backscatter imaging. For both vertical and sectional surfaces EDX analysis was used to characterize the surface composition in the tubular and inter-tubular area. Results Group A showed clean tubular lumina at all time points. From day 2 onwards dentin showed exposed collagen fibers. Group 2 initially showed a complete surface coverage that flattened out during treatment without ever exposing tubules. At baseline, samples of Group C displayed a complete homogeneous coverage. From day 2 on tubules entrances with obstructed lumen became visible. While on day 4 and 12 the dentin surface exposed collagen fibers the lumina remained closed. EDX analysis of the vertical and horizontal views showed that P and Ca were predominant elements in both the inter- and tubular dentin while Si peaks were found in the tubule plugs. Conclusion While group B displayed a packed layer on the surface during the whole investigation time group C samples lost their superficial layer within 48 h. Tubule plugs containing considerable Si proportions indicated previous presence of DentinoCer, while high Ca and P proportions suggest obturation by dentin-like material.

scholarly journals Peripheral Nerve Reconstruction after Injury: A Review of Clinical and Experimental Therapies

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
D. Grinsell ◽  
C. P. Keating
Keyword(s):  
Peripheral Nerve ◽  
Nerve Repair ◽  
Peripheral Nerve Regeneration ◽  
Surgical Techniques ◽  
The Body ◽  
Sensory Function ◽  
Nerve Reconstruction ◽  
Nerve Transfers ◽  
Experimental Therapies ◽  
Surgical Options

Unlike other tissues in the body, peripheral nerve regeneration is slow and usually incomplete. Less than half of patients who undergo nerve repair after injury regain good to excellent motor or sensory function and current surgical techniques are similar to those described by Sunderland more than 60 years ago. Our increasing knowledge about nerve physiology and regeneration far outweighs our surgical abilities to reconstruct damaged nerves and successfully regenerate motor and sensory function. It is technically possible to reconstruct nerves at the fascicular level but not at the level of individual axons. Recent surgical options including nerve transfers demonstrate promise in improving outcomes for proximal nerve injuries and experimental molecular and bioengineering strategies are being developed to overcome biological roadblocks limiting patient recovery.

Revascularization and Function of Pancreatic Islet Isografts in Diabetic Rats following Transplantation

2003 ◽  
Vol 12 (5) ◽  
pp. 537-544 ◽  
Author(s):  
Hajime Furuya ◽  
Toshihisa Kimura ◽  
Makoto Murakami ◽  
Kanji Katayama ◽  
Kazuo Hirose ◽  
...  
Keyword(s):  
Pancreatic Islet ◽  
Diabetic Rats ◽  
Isolated Islets ◽  
Diabetic Rat ◽  
Pancreatic Islet Transplantation ◽  
Intravenous Glucose ◽  
Lewis Rats ◽  
Group A ◽  
Group B ◽  
And Function

In pancreatic islet transplantation, revascularization is crucial for the graft's survival and function. In this study, the endothelium of isolated islets and revascularization and function of islet isografts in diabetic rat were investigated. Islets were isolated from Lewis rats by collagenase digestion method and were examined using immunohistochemistry (CD31 stain) on days 0, 1, 3, and 7 after isolation. The number of CD31-positive cells in these isolated islets was counted (mean ± SD%). Isografts (freshly isolated islets: group A, and islets cultured for 7 days: group B) transplanted in the renal subcapsule of streptozotocin-induced diabetic Lewis rats were examined using immunohistochemistry (CD31 stain) on days 3, 5, and 7 after transplantation. Intravenous glucose tolerance tests (IVGTT) were performed on days 3 and 7 after transplantation. The number of CD31-positive cells in the isolated islets on days 0, 1, 3, and 7 after isolation were: 17.3 ± 4.1%, 8.2 ± 0.7%, 2.1 ± 0.8%, and 0.8 ± 0.5%, respectively (p < 0.05). On day 5 after transplantation, CD31-positive cells were not detected in group A and B grafts, but were detected in both groups in periphery of the islets. On day 7, CD31-positive microvessels were present throughout the entire graft. IVGTT values in groups A and B on days 3 and 7 after transplantation did not show significant differences. In renal subcapsular isografts in diabetic rats, revascularization into islet grafts occurs from the surrounding host tissue 5 days after transplantation, but has no influence on the response to glucose during this period.

In vivo evaluation of poly(l-lactic acid) porous conduits for peripheral nerve regeneration

Biomaterials ◽  
1999 ◽  
Vol 20 (12) ◽  
pp. 1109-1115 ◽  
Author(s):  
G.R.D. Evans ◽  
K. Brandt ◽  
M.S. Widmer ◽  
L. Lu ◽  
R.K. Meszlenyi ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Peripheral Nerve Regeneration ◽  
In Vivo Evaluation

A New Formula for Population-Based Estimation of Whole Body Muscle Mass in Males

1997 ◽  
Vol 22 (6) ◽  
pp. 598-608 ◽  
Author(s):  
Malcolm B. Doupe ◽  
Alan D. Martin ◽  
Mark S. Searle ◽  
Dean J. Kriellaars ◽  
Gordon G. Giesbrecht
Keyword(s):  
Muscle Mass ◽  
Predictive Ability ◽  
Population Based ◽  
Fat Free Mass ◽  
Whole Body ◽  
Male Cadaver ◽  
Group A ◽  
New Equation ◽  
Group B ◽  
New Formula

A new equation to estimate muscle mass in males was developed using parameters common to the 1981 Canada Fitness Survey and the male cadaver data of Martin et al. (1990b). The cadavers (N = 12) were randomly divided into two groups. The equation was developed on cadaver Group A and then validated on Group B. Once the equation with the most suitable variables was validated on Group B, it was redeveloped on combined data from Groups A and B. The final equation is as follows: muscle mass (gm) = Ht (0.031MUThG2 + 0.064CCG2 + 0.089CAG2) −3.006; adjusted R2 = .96, SEE = 1,488 gm, F = 87.5, p = .0001. Variables (in cm) were Ht, height; MUThG, modified upper thigh girth; CCG, corrected calf girth; and CAG, corrected arm girth. The predictive ability of this equation was comparable to the original equation of Martin et al. (1990b) and can be a valuable tool for muscle mass estimation of male subjects in the 1981 Canada Fitness Survey. Key words: equation, estimation, body composition, body fat, fat free mass, lean body mass, Canada Fitness Survey

scholarly journals Effect of Anaesthesiologists’ Experience on Preferred Technique and Volume of Local Anaesthetic Administered for Brachial Plexus Nerve Block: A Retrospective Observational Analysis

2021 ◽  
Author(s):  
Depinder Kaur ◽  
Reena Mahajan ◽  
Shiv Kumar Singh ◽  
Suchitra Malhotra
Keyword(s):  
Peripheral Nerve ◽  
Brachial Plexus ◽  
Failure Rate ◽  
Nerve Block ◽  
Local Anaesthetic ◽  
Block Group ◽  
Nerve Blocks ◽  
Peripheral Nerve Blocks ◽  
Group A ◽  
Group B

Introduction: Faculty and Residents are trained in peripheral nerve blocks guided by blind technique, Peripheral Neuro Stimulator (PNS) or Ultrasound (USG) guided technique. But due to unavailability of USG machine in all institutes and requiring special training, techniques used for peripheral nerve blocks vary from institute to institute. Aim: To analyse the effect of anaesthesiologists’ experience on preferred technique and Local Anaesthetic (LA) volume used for brachial plexus nerve block retrospectively. Materials and Methods: In this retrospective observational study, 129 adults American Society of Anesthesiologists (ASA) grade I and II patients requiring brachial plexus nerve block for upper limb orthopaedic surgical anaesthesia for both elective and emergency surgery were divided into three groups for each year depending on technique for nerve block used. Group A: Received USG guided (Micromaxx Sonosite Inc, USA) brachial plexus nerve block. Group B: Received peripheral nerve stimulator (Inmed) guided brachial plexus nerve block. Group C: Received brachial plexus nerve block by traditional anatomical landmark based paraesthesia elicitation blind technique. Patients with inadequate surgical analgesia were given general anaesthesia and were categorised as failure rate. Year wise demographic data, type of technique used for giving brachial plexus nerve block, volume of drug used, failure rate, complications observed were collected and analysed by Student’s t-test and Chi-square test. Results: USG guided technique was the most prefered technique in both years (57.6%, n=38 in year 2018 and 49.2%, n=31 in year 2019). In remaining nearly half of the patients PNS and blind technique was used (PNS 24.2%, n=16 in year 2018 and 20.6%, n=13 in year 2019; blind technique 18.2%, n=12 in year 2018 and 30.2%, n=19 in year 2019). Significantly, less volume of LA drug (mL) was used in group A in year 2019 (16.43±6.07) than in year 2018 (22.34±4.75) (p<0.001). Failure rate in group A in year 2019 (3.2%) was significantly less than in year 2018 (5.2%), but the difference was insignificant in all three groups. In group A, no complications were observed in year 2019 while one incidence of hemidiaphragm paralysis was observed in year 2018, while in group B and C, complications were observed in both years. Conclusion: USG guided nerve block was the most preferred technique for nerve block in the study institute. In 24 months observation period, with increasing experience with USG there was significant increase in success rate and decrease in the volume of LA administered and complications.

Sign in / Sign up

Export Citation Format

Share Document