Biocompatibility of Hylan Polymers in Various Tissue Compartments

1995 ◽  
Vol 394 ◽  
Author(s):  
N.E. Larsen ◽  
E. Leshchiner ◽  
E.A. Balazs ◽  
C. Belmonte
Keyword(s):  
Adverse Effect ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Tissue Reaction ◽  
Tissue Response ◽  
Medical Applications ◽  
Biological Compatibility ◽  
Sciatic Nerves ◽  
Tissue Compartments

AbstractHylans (hyaluronan derivatives) retain the biological compatibility of the natural hyaluronan and have enhanced rheological properties which expands their utility in medical applications. Hylan materials (hylan A fluid, hylan B gel) were evaluated in a variety of tissue compartments for local and systemic tissue reaction (gross and microscopic), residence time and overall behavior in vivo. Hylan material was implanted into the subcutaneous, intradermal, submucosal, intramuscular, eye (vitreus, anterior chamber, trabecular meshwork), and neural (sciatic nerve) tissues at volumes ranging from 0.50 ml/kg to 20 ml/kg (2.5 mg/kg to 100 mg/kg). There was no difference in tissue response to hylan implants at the various ‘doses’ evaluated; all samples tested were observed to be biocompatible and did not elicit significant tissue response. Therefore, tissue reaction of hylan implants was not dependent on dose or concentration of hylan administered, since implantation of small amounts resulted in the same response as implantation of large amounts of material. In one of the most sensitive tests of biocompatibility, hylan was found to have no adverse effect on nerve regeneration (severed sciatic nerves in rat), and the results indicated that hylan materials “regeneration-friendly” environment for peripheral nerve growth as commatpearriaelds tpor othveid BedS Sa controls.Hylan materials provide biologically and physically compatible intercellular matrices which are useful in a variety of medical applications, including use as viscosurgical and viscoprotective tools (to maintain space, separate and protect tissues) and as viscosupplementation devices and implants.

Facilitated migration of cells from a transected peripheral nerve over collagen fibers: in vivo observations

1989 ◽  
Vol 47 ◽  
pp. 888-889
Author(s):  
Arthur J. Wasserman ◽  
Azam Rizvi ◽  
George Zazanis ◽  
Frederick H. Silver
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Collagen Gel ◽  
Collagen Fibers ◽  
Control Group ◽  
Guide Tube ◽  
Sprague Dawley ◽  
Silicone Tube ◽  
Thin Sections

In cases of peripheral nerve damage the gap between proximal and distal stumps can be closed by suturing the ends together, using a nerve graft, or by nerve tubulization. Suturing allows regeneration but does not prevent formation of painful neuromas which adhere to adjacent tissues. Autografts are not reported to be as good as tubulization and require a second surgical site with additional risks and complications. Tubulization involves implanting a nerve guide tube that will provide a stable environment for axon proliferation while simultaneously preventing formation of fibrous scar tissue. Supplementing tubes with a collagen gel or collagen plus extracellular matrix factors is reported to increase axon proliferation when compared to controls. But there is no information regarding the use of collagen fibers to guide nerve cell migration through a tube. This communication reports ultrastructural observations on rat sciatic nerve regeneration through a silicone nerve stent containing crosslinked collagen fibers.Collagen fibers were prepared as described previously. The fibers were threaded through a silicone tube to form a central plug. One cm segments of sciatic nerve were excised from Sprague Dawley rats. A control group of rats received a silicone tube implant without collagen while an experimental group received the silicone tube containing a collagen fiber plug. At 4 and 6 weeks postoperatively, the implants were removed and fixed in 2.5% glutaraldehyde buffered by 0.1 M cacodylate containing 1.5 mM CaCl2 and balanced by 0.1 M sucrose. The explants were post-fixed in 1% OSO4, block stained in 1% uranyl acetate, dehydrated and embedded in Epon. Axons were counted on montages prepared at a total magnification of 1700x. Montages were viewed through a dissecting microscope. Thin sections were sampled from the proximal, middle and distal regions of regenerating sciatic plugs.

scholarly journals The dynamic changes of main cell types in the microenvironment of sciatic nerves following sciatic nerve injury and the influence of let-7 on their distribution

RSC Advances ◽  
2018 ◽  
Vol 8 (72) ◽  
pp. 41181-41191 ◽  
Author(s):  
Tianmei Qian ◽  
Pan Wang ◽  
Qianqian Chen ◽  
Sheng Yi ◽  
Qianyan Liu ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Schwann Cells ◽  
Nerve Injury ◽  
Cell Types ◽  
Sciatic Nerve Injury ◽  
Dynamic Changes ◽  
Main Cell ◽  
Sciatic Nerves

Schwann cells (SCs), fibroblasts and macrophages are the main cells in the peripheral nerve stumps.

scholarly journals Wire Electrodes Embedded in Artificial Conduit for Long-term Monitoring of the Peripheral Nerve Signal

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 184 ◽  
Author(s):  
Woohyun Jung ◽  
Sunyoung Jung ◽  
Ockchul Kim ◽  
HyungDal Park ◽  
Wonsuk Choi ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Axon Regeneration ◽  
Scar Formation ◽  
Tissue Response ◽  
Nerve Signal ◽  
Long Term Monitoring ◽  
The Wire ◽  
Term Monitoring

Massive efforts to develop neural interfaces have been made for controlling prosthetic limbs according to the will of the patient, with the ultimate goal being long-term implantation. One of the major struggles is that the electrode’s performance degrades over time due to scar formation. Herein, we have developed peripheral nerve electrodes with a cone-shaped flexible artificial conduit capable of protecting wire electrodes from scar formation. The wire electrodes, which are composed of biocompatible alloy materials, were embedded in the conduit where the inside was filled with collagen to allow the damaged nerves to regenerate into the conduit and interface with the wire electrodes. After implanting the wire electrodes into the sciatic nerve of a rat, we successfully recorded the peripheral neural signals while providing mechanical stimulation. Remarkably, we observed the external stimuli-induced nerve signals at 19 weeks after implantation. This is possibly due to axon regeneration inside our platform. To verify the tissue response of our electrodes to the sciatic nerve, we performed immunohistochemistry (IHC) and observed axon regeneration without scar tissue forming inside the conduit. Thus, our strategy has proven that our neural interface can play a significant role in the long-term monitoring of the peripheral nerve signal.

scholarly journals Gellan Gum-based luminal fillers for peripheral nerve regeneration: an in vivo study in the rat sciatic nerve repair model

2018 ◽  
Vol 6 (5) ◽  
pp. 1059-1075 ◽  
Author(s):  
C. R. Carvalho ◽  
S. Wrobel ◽  
C. Meyer ◽  
C. Brandenberger ◽  
I. F. Cengiz ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Experimental Work ◽  
Nerve Repair ◽  
Peripheral Nerve Regeneration ◽  
Gellan Gum ◽  
In Vivo Study ◽  
Rat Sciatic Nerve

This experimental work considers the innovative use of the biomaterial Gellan Gum (GG) as a luminal filler for nerve guidance channels.

scholarly journals The Role of Adipose-Derived Mesenchymal Stem Cells in the Regeneration of Sciatic Nerve Injury in Rats

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
C R Saba ◽  
S M Abdeltawab ◽  
S M Omar ◽  
A A AboZeid
Keyword(s):  
Stem Cells ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Spontaneous Recovery ◽  
Control Group ◽  
Albino Rats ◽  
Sciatic Nerve Crush ◽  
Group I ◽  
S 100 ◽  
Sciatic Nerves

Abstract Background and Objectives experimentally, peripheral nerve repair can be enhanced by Schwann cell (SC) transplantation but the clinical application is limited by donor site morbidity and the inability to generate a sufficient number of cells. We have investigated whether stem cells, isolated from adipose tissue, can enhance the regeneration of crushed sciatic nerves in adult male albino rats. Materials and Methods we divided our rats into 3 groups of 10 rats each. Group I was the control group. Group II underwent crushing of their left sciatic nerves and were left for spontaneous recovery. Group III underwent crushing of their left sciatic nerves with local transplantation of ASCs around the injured nerve. We then compared the effect of spontaneous recovery versus local injection of ASCs in the regeneration of the nerves. Results The results were evaluated 4 weeks postoperative; sciatic nerves were stained by H&E, and immunohistochemically using S-100. The results showed a significant increase in axonal regeneration with the ASCs treated group compared to the spontaneous recovery one. Conclusion Our results suggested that ASCs have a beneficial role in treatment of peripheral nerve injuries. Keywords ASCs, Sciatic nerve crush injury, S-100

Waterjet Dissection of Peripheral Nerves: An Experimental Study of the Sciatic Nerve of Rats

2010 ◽  
Vol 67 (suppl_2) ◽  
pp. ons368-ons376 ◽  
Author(s):  
Christoph A. Tschan ◽  
Doerthe Keiner ◽  
Harald D. Müller ◽  
Kerstin Schwabe ◽  
Michael R. Gaab ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Peripheral Nerves ◽  
Scar Tissue ◽  
Small Water ◽  
Peripheral Nerve Surgery ◽  
Sciatic Nerves ◽  
Nerve Surgery ◽  
Waterjet Dissection

ABSTRACT BACKGROUND: Although waterjet dissection has been well evaluated in intracranial pathologies, little is known of its qualities in peripheral nerve surgery. Theoretically, the precise dissection qualities could support the separation of nerves from adjacent tissues and improve the preservation of nerve integrity in peripheral nerve surgery. OBJECTIVE: To evaluate the potential of the new waterjet dissector in peripheral nerve surgery. METHODS: Waterjet dissection with pressures of 20 to 80 bar was applied on the sciatic nerves of 101 rats. The effect of waterjet dissection on the sciatic nerve was evaluated by clinical tests, neurophysiological examinations, and histopathological studies up to 12 weeks after surgery. RESULTS: With waterjet pressures up to 30 bar, the sciatic nerve was preserved in its integrity in all cases. Functional damaging was observed at pressures of 40 bar and higher. However, all but 1 rat in the 80 bar subgroup showed complete functional regeneration at 12 weeks after surgery. Histopathologically, small water bubbles were observed around the nerves. At 40 bar and higher, the sciatic nerves showed signs of direct nerve injury. However, all these animals showed nerve regeneration after 12 weeks, as demonstrated by histological studies. CONCLUSION: Sciatic nerves were preserved functionally and morphologically at pressures up to 30 bar. Between 40 and 80 bar, reliable functional and morphological nerve regeneration occurred. Waterjet pressures up to 30 bar might be applied safely under clinical conditions. This technique might be well suited to separate intact peripheral nerves from adjacent tumor or scar tissue. Further studies will have to show the clinical relevance of these dissection qualities.

VULNERABILITY OF THE GRADUALLY ELONGATED NERVE TO COMPRESSION INJURY

Hand Surgery ◽  
2001 ◽  
Vol 06 (01) ◽  
pp. 29-35 ◽  
Author(s):  
Kazuo Ikeda ◽  
Mitsuteru Yokoyama ◽  
Katsuro Tomita ◽  
Shigenori Tanaka
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Control Group ◽  
Severe Damage ◽  
Compression Injury ◽  
Sciatic Nerves

The purpose of this study is to clarify the vulnerability of the gradually elongated peripheral nerve. Rabbit's sciatic nerves were gradually elongated to 30 mm at the rate of 2.0 mm/day and 4.0 mm/day. Immediately after elongation, the sciatic nerve was exposed and compressed for 30 minutes at various forces, 15, 30 and 60 g/0.1 cm2. Immediately after elongation and compression, 2, 4 and 8 weeks after compression, each group was electrophysiologically and histologically estimated — 15 g/0.1 cm2 caused no damage to the control group, neurapraxia to the 2.0 mm/day group, and axonotmesis to the 4.0 mm/day group; 30 g/0.1 cm2 caused neurapraxia to the control group and axonotmesis to the 2.0 mm/day group; 60 g/0.1 cm2 caused axonotmesis to the control group and slowly recovered axonotmesis to the 2.0 mm/day group. This study shows that though mild compression, does not cause nerve injury to the intact nerve, it can sometimes cause severe damage to the gradual elongated nerve.

EFFECTS OF LIGUSTICUM CHUANXIONG ON INJURED PERIPHERAL NERVE IN RATS

2010 ◽  
Vol 22 (04) ◽  
pp. 315-320 ◽  
Author(s):  
Chao-Tsung Chen ◽  
Jaung-Geng Lin ◽  
Tung-Wu Lu ◽  
Chih-Yang Huang ◽  
Chin-Chuan Tsai ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Silicone Rubber ◽  
Critical Factor ◽  
The Other ◽  
High Dose ◽  
Negative Effects ◽  
Ligusticum Chuanxiong

The present study provides in vivo trials of silicone rubber chambers filled with different concentrations (0, 1.25, 12.5, and 125 mg/ml) of Ligusticum Chuanxiong (LC) to bridge a 10 mm sciatic nerve defect in rats. Histological and electrophysiological techniques were used to evaluate the functional recovery of the nerve. At the end of eight weeks, regenerated nerves from all of the groups treated with the LC had similar microstructures compared to the controls. However, the high dose LC group at 125 mg/ml could inhibit the nerve regeneration with a significantly fewer myelinated axons compared to the other three groups. These results indicated that LC could be involved in both positive and negative effects on regenerating nerves. Therefore, whether a proper dosage of an LC is used or not plays a critical factor in deciding if it can sustain nerve regeneration over long gaps.

Effect of Arecoline on Regeneration of Injured Peripheral Nerves

2013 ◽  
Vol 41 (04) ◽  
pp. 865-885 ◽  
Author(s):  
Sheng-Chi Lee ◽  
Chin-Chuan Tsai ◽  
Chun-Hsu Yao ◽  
Yuan-Man Hsu ◽  
Yueh-Sheng Chen ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Peripheral Nerve Regeneration ◽  
In Vitro Study ◽  
Control Group ◽  
Neural Cells ◽  
In Vivo Evaluation

The present study provides in vitro and in vivo evaluation of arecoline on peripheral nerve regeneration. In the in vitro study, we found that arecoline at 50 μg/ml could significantly promote the survival and outgrowth of cultured Schwann cells as compared to the controls treated with culture medium only. In the in vivo study, we evaluated peripheral nerve regeneration across a 10-mm gap in the sciatic nerve of the rat, using a silicone rubber nerve chamber filled with the arecoline solution. In the control group, the chambers were filled with normal saline only. At the end of the fourth week, morphometric data revealed that the arecoline-treated group at 5 μg/ml significantly increased the number and the density of myelinated axons as compared to the controls. Immunohistochemical staining in the arecoline-treated animals at 5 μg/ml also showed their neural cells in the L4 and L5 dorsal root ganglia ipsilateral to the injury were strongly retrograde-labeled with fluorogold and lamina I–II regions in the dorsal horn ipsilateral to the injury were significantly calcitonin gene-related peptide-immunolabeled compared with the controls. In addition, we found that the number of macrophages recruited in the distal sciatic nerve was increased as the concentration of arecoline was increased. Electrophysiological measurements showed the arecoline-treated groups at 5 and 50 μg/ml had a relatively larger nerve conductive velocity of the evoked muscle action potentials compared to the controls. These results indicate that arecoline could stimulate local inflammatory conditions, improving the recovery of a severe peripheral nerve injury.

scholarly journals In Vivo Investigation of Soft Tissue Response of Novel Silver/Poly(Vinyl Alcohol)/ Graphene and Silver/Poly(Vinyl Alcohol)/Chitosan/Graphene Hydrogels Aimed for Medical Applications – The First Experience

2018 ◽  
Vol 68 (3) ◽  
pp. 321-339 ◽  
Author(s):  
Tijana Lužajić Božinovski ◽  
Danica Marković ◽  
Vera Todorović ◽  
Bogomir Prokić Bolka ◽  
Ivan Milošević ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Vinyl Alcohol ◽  
Subcutaneous Tissue ◽  
Tissue Response ◽  
Surrounding Tissue ◽  
Poly Vinyl Alcohol ◽  
Medical Applications ◽  
Capsule Thickness ◽  
Soft Tissue Response

Abstract In this paper, we have shown for the fi rst time the soft tissue response of novel silver/ poly(vinyl alcohol)/graphene (Ag/PVA/Gr) and silver/poly(vinyl alcohol)/chitosan/ graphene (Ag/PVA/CHI/Gr) nanocomposite hydrogels aimed for medical applications. These novel hydrogels were produced by in situ electrochemical synthesis of silver nanoparticles in the polymer matrices as described in our previously published works. Both Ag/PVA/Gr and Ag/PVA/CHI/Gr, as well as controls Ag/PVA, Ag/PVA/CHI and commercial Suprasorb©hydrogel discs, were implanted in the subcutaneous tissue of rats. Implants with the surrounding tissue were dissected after post-implantation on days 7, 15, 30 and 60, and then processed for histological examination. The tissue irritation index (TIrI) score, according to ISO 10993-6, 2007, as well as the number of leukocytes in the peri-implant zone and connective tissue capsule thickness were examined. The results show that each TIrI score, the leukocyte number around the implanted materials and capsule thickness gradually decreased during the observation period. At the endpoint of follow-up, the Ag/PVA/CHI/Gr implant was surrounded with a thinner capsule, while both the TIrI score and the number of leukocytes of the peri-implant zone were greater compared to the Ag/PVA/Gr implant. Despite the observed differences, we can conclude that our in vivo experiment suggested that both novel hydrogels were biocompatible and suitable for medical use.

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