Ammonium hydroxide modification of polylactic acid and polyglycolic acid monofilaments for acupoint catgut embedding therapy

2020 ◽  
Vol 90 (17-18) ◽  
pp. 2109-2119
Author(s):  
Shaoju Fu ◽  
Yao Lu ◽  
Peihua Zhang
Keyword(s):  
Surface Modification ◽  
Polylactic Acid ◽  
Cell Attachment ◽  
Ammonium Hydroxide ◽  
Polyglycolic Acid ◽  
Embedding Therapy ◽  
Surface Modified ◽  
Future Work ◽  
Wide Usage

Polylactic acid (PLA) and polyglycolic acid (PGA) monofilaments have attracted much attention for their wide usage in acupoint catgut embedding therapy (ACET). Their application is restricted, however, by their poor hydrophilicity and cell attachment properties. In this study, PLA and PGA monofilaments were produced from polymer chips, and then modified by the application of an ammonium hydroxide solution to the surface. The modified PLA and PGA monofilaments were fully characterized with respect to their structural, mechanical, and in-vitro properties. The results showed that the surface roughness and hydrophilicity of the materials were greatly increased; surface modified samples of both materials exhibited the smallest contact angle values: 79.2° ± 2.5° (sample PLA2) and 75.9° ± 1.4° (sample PGA2). The weights and diameters and the tensile and flexibility properties of the materials changed little with surface modification, but their swelling ratios increased significantly. All the prepared samples were non-toxic (more than 75% of cells being viable). Surface modification also enhanced cell attachment: PLA2 (48.15% ± 2.16%) and PGA2 (59.43% ± 3.18%) showed the largest cell attachment values (cultured for 48 h) among the samples. In summary, the study proves the feasibility of ammonium hydroxide modification of PLA and PGA, which is beneficial for guiding future work on developing functional PLA or PGA materials for ACET.

Surface modification of polylactic acid (PLA) and polyglycolic acid (PGA) monofilaments via the cold plasma method for acupoint catgut-embedding therapy applications

2019 ◽  
Vol 89 (18) ◽  
pp. 3839-3849 ◽  
Author(s):  
Shaoju Fu ◽  
Peihua Zhang
Keyword(s):  
Surface Modification ◽  
Polylactic Acid ◽  
Cold Plasma ◽  
Cell Attachment ◽  
Polyglycolic Acid ◽  
Oxygen Plasma Treatment ◽  
Plasma Method ◽  
Embedding Therapy ◽  
Good Cell

Polylactic acid (PLA) and polyglycolic acid (PGA) monofilaments have been the most recently, widely used acupoint catgut-embedding therapy (ACET) biodegradable materials. However, their poor hydrophilicity and cell adhesion are common limitations during applications. To improve their surface properties, modification technologies should be generally applied. This paper firstly adapted polymer chips to produce four types of PLA and PGA monofilaments, and then attempted cold oxygen plasma treatment for surface modification. Afterwards, the modified monofilaments were fully characterized with respect to structure, mechanical and in vitro properties. The results showed that both the PLA and PGA monofilaments became coarser after modification, and their hydrophilicity was improved, while their weight and diameter sizes were slightly decreased. The tensile properties and flexibility of the modified samples changed little, and their swelling ratio increased sharply. All the prepared samples exhibited good cell viability, with more than 75% of cells being viable. Sample PM-PLA2 (plasma-modified PLA2) and sample PM-PGA2 (plasma-modified PGA2) presented the largest cell attachment ratio (cultured for 48 h) at 52.16% ± 1.05% and 58.39% ± 2.07%, respectively. In sum, this cold plasma method successfully improved the hydrophilicity and in vitro properties of PLA and PGA monofilaments, while retaining the other excellent properties, and warrants further study to develop new PLA and PGA-embedding materials with outstanding clinical efficacy.

A study of ultrasound/H2O2 combined surface modification on polyglycolic acid monofilaments for acupoint catgut embedding therapy application

2018 ◽  
Vol 89 (15) ◽  
pp. 3112-3126
Author(s):  
Shaoju Fu ◽  
Dongchao Yang ◽  
Cunyi Zhao ◽  
Peihua Zhang
Keyword(s):  
Surface Modification ◽  
Cell Attachment ◽  
Polyglycolic Acid ◽  
Contact Angles ◽  
Swelling Behavior ◽  
Polar Groups ◽  
Embedding Therapy ◽  
Ft Ir ◽  
Ir Analysis

Polyglycolic acid (PGA) monofilament has been regarded as an excellent acupoint catgut embedding therapy (ACET) material because it offers numerous advantages, including easy accessibility and good forming and degradable properties. However, the poor hydrophilicity and cytocompatibility are the main disadvantages preventing it from having wider applications. In this communication, two types of PGA monofilaments were first fabricated from their polymer chips, followed by ultrasound/H2O2 combined surface modification at 1:1 (V/V), and different ultrasound frequencies (45, 60 and 75 KHz) were explored. The modified PGA monofilaments were fully characterized with respect to structure characterizations (surface morphology, weights and diameters, Fourier transform infrared spectroscopy (FT-IR) analysis and hydrophilicity), mechanical properties (tensile property, swelling behavior and flexibility) and in vitro properties (cytotoxicity, cell attachment and cell morphology). The results showed that the PGA monofilaments after modification would become coarser, with larger weights and diameters. Samples 1-PGA 75 and 2-PGA 75 exhibited the smallest contact angles at 70.51° ± 3.27° and 62.84° ± 2.53°, respectively. The FT-IR analysis results confirmed that some polar groups emerged, promoting the hydrophilicity of PGA monofilaments. The swelling behavior of monofilaments was enhanced, while tensile and bending stiffness values slightly decreased. All the prepared samples presented no toxicity, and the cell attachment ratio (cultured for 48 h) of PGA monofilaments had been greatly improved after modification. These findings present important clinical implications in the ACET materials manufacturing process and warrant further study to develop new PGA embedding materials with outstanding clinical efficacy.

Comparison of polyglycolic acid acupoint catgut embedding therapy monofilaments for a juvenile pseudo-myopia surface modified by two processing methods

2019 ◽  
Vol 89 (19-20) ◽  
pp. 4071-4082 ◽  
Author(s):  
Shaoju Fu ◽  
Yao Lu ◽  
Peihua Zhang
Keyword(s):  
Cell Attachment ◽  
Surface Modifications ◽  
Polyglycolic Acid ◽  
Practical Application ◽  
Processing Methods ◽  
Comprehensive Properties ◽  
Embedding Therapy ◽  
Surface Modified ◽  
Plasma Technologies

Polyglycolic acid (PGA) acupoint catgut embedding therapy (ACET) monofilament has been heavily used for juvenile pseudopia in the recent years. However, poor hydrophilicity and cytocompatibility have limited its development and wide practical application. In this context, this work is aimed to develop ACET materials with good comprehensive properties by surface modifications.  Two different methods, namely ultrasound and plasma technologies, were selected to modify the surface property of PGA monofilaments to improve their wetting and compatibility with tissues, while minimizing degradation of the fibers. Moreover, the effects of these two processing methods on the structure, mechanical and in vitro properties of PGA were fully characterized.  Both the ultrasound and plasma modified samples were observed to have a larger surface roughness, and their weights and diameters were decreased. Samples P-PGA1 (76.2° ± 1.4°) and P-PGA2 (73.5° ± 1.9°) exhibited the smallest contact angle values among their groups, respectively. The tensile properties and bending stiffness values of modified PGA decreased slightly, while their swelling ratios were greatly improved. All the prepared samples presented no toxicity (more than 75% cells being viable), and their cell attachment ratios (cultured for 48 h) were also enhanced.  In summary, plasma and ultrasound modified PGA showed better hydrophilicity and in vitro properties compared to that of unmodified samples, while retaining the other excellent characteristics. These findings illustrated that the two processing methods were feasible and warrant further study in the application of ACET materials.

Ultrasonic modification of polylactic acid and polyglycolic acid acupoint catgut embedding monofilaments for juvenile pseudomyopia

2018 ◽  
Vol 89 (17) ◽  
pp. 3556-3566 ◽  
Author(s):  
Shaoju Fu ◽  
Dongchao Yang ◽  
Cunyi Zhao ◽  
Peihua Zhang
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
High Efficiency ◽  
Cell Attachment ◽  
Polyglycolic Acid ◽  
Molecular Structures ◽  
Ultrasonic Power ◽  
Mixed Solution ◽  
Ultrasonic Modification

Acupoint catgut embedding therapy (ACET) has become the most promising method for treatment of juvenile pseudomyopia due to its advantages of lasting effect, high efficiency, safety and no side effects. However, poor hydrophilicity and biocompatibility are the main disadvantages, preventing ACET materials from having wide applications. This work fabricated four types of polylactic acid (PLA) and polyglycolic acid (PGA) monofilaments from their polymer chips, and then the prepared monofilaments were treated ultrasonically by dipping them in a mixed solution composed of ethyl alcohol and H2O2(volume ratio 1:1) at 250 W ultrasonic power for 30 min. Afterwards, the PLA and PGA groups were fully characterized with respect to structure characterizations, mechanical properties and in vitro properties. The results showed that the surface roughness of the monofilaments had been greatly enhanced by ultrasonic modification. The PLA groups’ molecular structures changed little, while those of the PGA group emerged with some polar hydrophilic bonds. By deionized water measurement of contact angle values, the ultrasound modified PLA monofilaments (UMPLA1 = 87.2 ± 2.5°, UMPLA2 = 83.6 ± 3.5°) presented a decrease compared to that of untreated PLA ones (PLA1 =103.5 ± 3.4°, PLA2 = 108.4 ± 1.2°), while that of ultrasound modified PGA monofilaments (UMPGA1 = 75.6 ± 4.3°, UMPGA2 =70.5 ± 3.1°) was smaller than untreated PGA ones (PGA1 = 97.3 ± 1.7°, PGA2 = 95.8 ± 2.6°). Based on the measurement of the mechanical properties, the tensile properties and bending stiffness of the PLA and PGA groups changed little, and their swelling ratios were greatly improved after modification. All the prepared monofilaments presented non-toxicity with good cell viability (more than 75%), and samples UMPGA2 (81.4 ± 3.1%) and UMPLA2 (65.8 ± 0.8%) exhibited the largest cell attachment ratio values among their groups. In conclusion, these findings present important clinical implications regarding the ACET materials manufacturing process, which warrant further study.

scholarly journals DEGRADASI POLIBLEND POLI(ASAMLAKTAT-KO-ASAMGLIKOLAT) DENGAN POLI(ε-KAPROLAKTON) SECARA IN VITRO

2015 ◽  
Vol 2 (2) ◽  
pp. 174
Author(s):  
Tetty Kemala ◽  
Achmad Sjahriza ◽  
Hendra Adijuwana ◽  
Mardiana Hardianti
Keyword(s):  
Lactic Acid ◽  
Polylactic Acid ◽  
Intrinsic Viscosity ◽  
Phosphate Buffer ◽  
Glycolic Acid ◽  
Incubation Temperature ◽  
Human Life ◽  
Polyglycolic Acid ◽  
Poly Lactic Acid

 ABSTRACT  Polymer has many applications in human life, one of them is in the field of health. Polymer synthetics like polylactic acid (PLA), polyglycolic acid (PGA), poly(ε-caprolactone) (PCL), and poly(lactic acid-co-glycolic acid) (PLGA) were kind of polyesters that is many used in field   of health. Many researchers have already made research about degradation of PLA, PGA, PCL, and PLGA. However, there is no one doing research about degradation of combination between this two polymers, one of them is polyblend of  PLGA and PCL. Polyblend were made of four compositions, that were PLGA(90:10):PCL 3:1, PLGA(75:25):PCL 3:1, PLGA(90:10):PCL 5:1, and PLGA(75:25):PCL 5:1. Degradation was carried out for eight weeks by using phosphate buffer pH 7.4 and incubation temperature of 37°C. Degradation of the polymer was observed by mass remained, and intrinsic viscosity. The result showed that composition PLGA(75:25):PCL 5:1 was the fastest in degradation compared to other compositions. It was showed by the decrease in mass until 89.06% and the change in intrinsic viscosity until 20.13%. Keywords: PLGA, PCL   

In-vitro Comparative Assessment of Antibacterial and Anti-adherent Effect of Two Types of Surface Modificants on Stainless Steel Orthodontic Brackets Against Streptococcus mutans

2021 ◽  
pp. 030157422110372
Author(s):  
Mrunmaye Math ◽  
Alok G. Shah ◽  
Parag Gangurde ◽  
Anita G. Karandikar ◽  
Anjali Gheware ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Surface Modification ◽  
Streptococcus Mutans ◽  
Rf Magnetron Sputtering ◽  
Orthodontic Brackets ◽  
P Value ◽  
Bacterial Cells ◽  
Colony Forming Units ◽  
Surface Modified

Objective: Comparative evaluation of antibacterial and anti-adherent properties of surface-modified stainless steel (SS) orthodontic brackets against Streptococcus mutans ( S. mutans). Materials and Methods: The study was conducted on 120 SS orthodontic McLaughlin, Bennett, Trevisi (MBT) 0.022″ slot by Leone, Italy. Orthodontic brackets that constituted the sample size were divided into 6 groups, consisting of 20 samples each in two control (non-surface coated) and four experimental groups. The experimental group’s surface coatings were photocatalytic zinc oxide (ZnO) and photocatalytic titanium oxide (TiO2), which were carried out by radiofrequency (RF) magnetron sputtering method for surface modification. Brackets were subjected to microbiological tests against S. mutans. For anti-adherence, weight change, pre- and postexposure, was evaluated to gauge the adherence of bacteria and colony-forming units/milliliter (CFU/mL) count measuring the survival rate of bacterial cells for antibacterial activity. Results: The TiO2-coated group showed statistically significant anti-adherence ( P-value < .05) against S. mutans than control and ZnO groups. The CFU count of TiO2 group was lower than control as well as ZnO group. Conclusion: TiO2 is superior to ZnO and should be continued to be considered for surface modification of orthodontic brackets against White Spot Lesions (WSLs) and gingivitis.

SURFACE MODIFICATION OF NITINOL BY CHEMICAL AND ELECTROCHEMICAL ETCHING

2013 ◽  
Vol 27 (19) ◽  
pp. 1341012 ◽  
Author(s):  
ZHENDI YANG ◽  
XIAOJIN WEI ◽  
PENG CAO ◽  
WEI GAO
Keyword(s):  
Surface Modification ◽  
Biomedical Applications ◽  
Cell Attachment ◽  
Electrochemical Etching ◽  
Nickel Content ◽  
Corrosion Property ◽  
X Ray ◽  
Ni Content ◽  
Etching Parameters ◽  
Surface Modified

In this paper, Nitinol, an equiatomic binary alloy of nickel and titanium, was surface modified for its potential biomedical applications by chemical and electrochemical etching. The main objective of the surface modification is to reduce the nickel content on the surface of Nitinol and simultaneously to a rough surface microstructure. As a result, better biocompatibility and better cell attachment would be achieved. The effect of the etching parameters was investigated, using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometry (EDX) and X-ray photoelectron spectrometry (XPS). The corrosion property of modified Nitinol surfaces was investigated by electrochemical work station. After etching, the Ni content in the surface layer has been reduced and the oxidation of Ti has been enhanced.

A study of the chitosan coating method on polyglycolic acid and polylactic acid embedding monofilaments

2017 ◽  
Vol 89 (3) ◽  
pp. 270-280 ◽  
Author(s):  
Shao-ju Fu ◽  
Pei-hua Zhang
Keyword(s):  
Polylactic Acid ◽  
Polyglycolic Acid ◽  
Minimal Invasiveness ◽  
Chitosan Coating ◽  
Embedding Therapy ◽  
Coating Method ◽  
Deformation Ability ◽  
Experimental Process ◽  
Coating Weight ◽  
Swelling Behaviors

With the development of applying acupoint catgut embedding therapy to the treatment of juvenile pseudomyopia, embedding materials are expected to be the perfect for choice by taking advantage of the lasting effect and minimal invasiveness. This work adopted polyglycolic acid (PGA) and polylactic acid (PLA) monofilaments to produce four types of chitosan coated monofilaments with excellent swelling behaviors. For achieving better coating weight gains, a one-dipping-one-rolling coating system was developed. The results showed that both the PGA and PLA monofilaments' swelling behaviors were greatly improved, CS-PGA2 (98.17 ± 3.15%) presented a great difference from CS-PLA1 (47.56 ± 6.15%) and CS-PLA2 (63.31 ± 3.26%), respectively, while CS-PGA1 (87.36 ± 5.16%) had a similar expansion rate to that of CS-PGA2. The resist deformation ability of the monofilament was strengthened and the crystalline zones of PGA and PLA monofilaments were slightly decreased after a chitosan coating process. The CS-PGA group and PGA group were found to degrade completely in 56 days and 70 days, respectively, while the PLA group changed little in the experimental process, offering a new insight into controlled degradation research. In conclusion, all coated monofilaments show potential in acting as embedding materials with good swelling behaviors, and the CS-PGA group is proved to have a higher prospect for clinical applications.

Fabrication and evaluation of polylactic acid/pectin composite scaffold via freeze extraction for tissue engineering

2020 ◽  
Vol 40 (5) ◽  
pp. 421-431
Author(s):  
Mohd Syahir Anwar Hamzah ◽  
Saiful Izwan Abd Razak ◽  
Mohammed Rafiq Abdul Kadir ◽  
Siti Pauliena Mohd Bohari ◽  
Nadirul Hasraf Mat Nayan ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Polylactic Acid ◽  
Cell Attachment ◽  
Porous Scaffold ◽  
Composite Scaffold ◽  
Engineering Material ◽  
Water Contact ◽  
Good Biocompatibility ◽  
Proliferation In Vitro

AbstractThis work reports the fabrication and characterizations of porous scaffold made up of polylactic acid (PLA) with the inclusion of pectin (1, 3, 5, 7, 9, 11 wt%) for potential tissue engineering material. The composite scaffold was prepared using a facile method of freeze extraction. Based on the physical evaluations, the scaffold was suggested to be optimum at 5 wt% of pectin loading. Water contact angle of the scaffold was significantly reduced to 46.5o with the inclusion of 5 wt% of pectin. Morphological and topographic of the PLA scaffold revealed that the pectin induced more porous structure and its surface became rougher which was suitable for cell attachment and proliferation. In vitro studies of the PLA/pectin composite scaffold using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidelt (MTT) assay revealed good biocompatibility whereas Live-Dead kit assay resulted in 91% cell viability after 7 days of incubation.

Biological functionalization of poly (lactic-co-glycolic acid) with ammonia and chitosan–gelatin combined treatment for acupoint catgut-embedding therapy

2021 ◽  
pp. 004051752198927
Author(s):  
Shaoju Fu ◽  
Peihua Zhang
Keyword(s):  
Mechanical Properties ◽  
Glycolic Acid ◽  
Combined Treatment ◽  
Antibacterial Properties ◽  
Ammonia Solution ◽  
Embedding Therapy ◽  
Gelatin Coating ◽  
Surface Modified ◽  
And Staphylococcus Aureus

Polylactic-co-glycolic acid (PLGA) has attracted extensive attention in acupoint catgut embedding therapy (ACET). However, developing biological functionalization for ACET materials remains challenging to due to its poor surface properties. In this work, PLGA was first treated with ammonia solution, and chitosan–gelatin coating was then introduced onto the surface of PLGA braided thread to achieve biological functionalization. Characteristics such as structural, mechanical, and in vitro properties were then fully evaluated. The results showed that modified samples showed more surface roughness than non-modified ones, and weight and diameter changes in samples increased after coating treatment, together with surface hydrophilicity; mechanical properties such as tensile property and bending stiffness of samples were greatly enhanced. Non-coated samples exhibited no antibacterial properties, while that of coated samples showed different antibacterial properties against Escherichia coli and Staphylococcus aureus. No samples showed toxicity, with more than 75% cells viable. In sum, the strategy of surface-modified PLGA using a combined ammonia and chitosan–gelatin treatment showed great potential in the application of ACET.

Sign in / Sign up

Export Citation Format

Share Document