Abstract:The present paper is focused on the surface and bulk characterization of poly(lactic acid) (PLA)-based composites that contain hydrolyzed collagen as a biological polymer, silver nanoparticles and vitamin E and epoxidized soybean oil as a plasticizer. The bionanocomposites were obtained by melt processing and evaluated for structural and surface characteristics, biocompatibility, functional properties such as antimicrobial and antioxidant activity and hydrolytic degradation behavior. It has been established th… Show more
“…60 The average surface composition of two samples given in Table 6 is close to the experimental one. 60 determined from DSC and differential thermal analysis (DTA) curves ( Figure 9 and Table 7).…”
Section: Morphologysupporting
confidence: 70%
“…The multifunctionality and biocompatibility characteristics are evidenced by the results given in the second part of this research work. 60 Your contribution will be forwarded to the author(s) for a reply and, if considered appropriate by the editorin-chief, will be published as a discussion in a future issue of the journal.…”
The present study focused on the development of biocompatible antimicrobial/antioxidant biodegradable bionanocomposite renewable resources based on poly(lactic acid) (PLA) plasticised with epoxidised soybean oil. To the main PLA matrix hydrolysed collagen (HC) (to enhance biocompatibility), vitamin E (as antioxidant agent) and silver (Ag) nanoparticles (NPs) (for imparting antimicrobial properties for medical applications and also for active packaging) were incorporated. The blends were produced by using the classical technological flow of melt processing.The presence of the additives in the PLA matrix improved the processability and flexibility and slightly decreased the thermal properties. The specific interactions of silver NPs with the other components of nanocomposites, mainly with HC protein and vitamin E (by ionic and other types of secondary bonds), led to a better HC and vitamin E dispersion in the samples with a higher silver content (1·5%), which further caused the enhancement of the mechanical properties for high silver NP concentration. Therefore, the silver NPs were successfully embedded into the polymer matrix. The aim of this research was to improve the flexibility, biocompatibility and functionality of PLA and to obtain bionanocomposites destined for medical applications such as catheters. This first part of research deals with mechanical and thermal characterisation correlated with morphological features. Notation d 2 dimension coefficient according with Avrami-Erofeev model E 1 ,E 2 activation energies for each step n dimensional nucleation Avrami-Erofeev reaction model n 1 ,n 2 reaction orders R correlation coefficient s thermal process in one step T 10 temperature corresponding to 10 wt% mass loss T 50 temperature corresponding to 50 wt% mass loss T cc cold crystallization temperature T g glass transition temperature T m melting temperature T onset onset temperature of each thermogravimetric step TQ 1min torque after 1 min of melt processing TQ 5min torque after 5 min of melt processing TQ fin torque at end of melt processing TQ max maximum torque value on the torque-time curve W mass loss for each thermogravimetric stage W r,500°C residual mass loss DC p specific heat capacity DH cc cold crystallization enthalpy DH m melting enthalpy
“…60 The average surface composition of two samples given in Table 6 is close to the experimental one. 60 determined from DSC and differential thermal analysis (DTA) curves ( Figure 9 and Table 7).…”
Section: Morphologysupporting
confidence: 70%
“…The multifunctionality and biocompatibility characteristics are evidenced by the results given in the second part of this research work. 60 Your contribution will be forwarded to the author(s) for a reply and, if considered appropriate by the editorin-chief, will be published as a discussion in a future issue of the journal.…”
The present study focused on the development of biocompatible antimicrobial/antioxidant biodegradable bionanocomposite renewable resources based on poly(lactic acid) (PLA) plasticised with epoxidised soybean oil. To the main PLA matrix hydrolysed collagen (HC) (to enhance biocompatibility), vitamin E (as antioxidant agent) and silver (Ag) nanoparticles (NPs) (for imparting antimicrobial properties for medical applications and also for active packaging) were incorporated. The blends were produced by using the classical technological flow of melt processing.The presence of the additives in the PLA matrix improved the processability and flexibility and slightly decreased the thermal properties. The specific interactions of silver NPs with the other components of nanocomposites, mainly with HC protein and vitamin E (by ionic and other types of secondary bonds), led to a better HC and vitamin E dispersion in the samples with a higher silver content (1·5%), which further caused the enhancement of the mechanical properties for high silver NP concentration. Therefore, the silver NPs were successfully embedded into the polymer matrix. The aim of this research was to improve the flexibility, biocompatibility and functionality of PLA and to obtain bionanocomposites destined for medical applications such as catheters. This first part of research deals with mechanical and thermal characterisation correlated with morphological features. Notation d 2 dimension coefficient according with Avrami-Erofeev model E 1 ,E 2 activation energies for each step n dimensional nucleation Avrami-Erofeev reaction model n 1 ,n 2 reaction orders R correlation coefficient s thermal process in one step T 10 temperature corresponding to 10 wt% mass loss T 50 temperature corresponding to 50 wt% mass loss T cc cold crystallization temperature T g glass transition temperature T m melting temperature T onset onset temperature of each thermogravimetric step TQ 1min torque after 1 min of melt processing TQ 5min torque after 5 min of melt processing TQ fin torque at end of melt processing TQ max maximum torque value on the torque-time curve W mass loss for each thermogravimetric stage W r,500°C residual mass loss DC p specific heat capacity DH cc cold crystallization enthalpy DH m melting enthalpy
“…[ 83 ] have shown that cell (fibroblast) spreading appeared to be dependent on the polar surface free energy. Cell spreading is low when the SFE’s polar part of the material is lower than 5 mN/m, and marked spreading occurs when is higher than 15 mN/m [ 43 ]. Based on the values of the SFE polar part determined for the PLA/R composites, it can be assumed that the sample incorporating all the components (PLA/PEG/0.5R) will give better spreading and division of the fibroblasts because their takes an intermediary value.…”
Section: Resultsmentioning
confidence: 99%
“…For more details on the method see references [ 38 , 39 ]. To determine the surface free energy (SFE) components, the CA at equilibrium between the film surface and three pure liquids (in addition to water, methylene iodide, and formamide were used, as-purchased at maximum obtainable purity) were measured by fitting the drop profile using the Young-Laplace equation [ 40 , 41 , 42 , 43 ]. The acid/base (LW/AB) approach of van Oss and Good, see Equation (4) [ 44 , 45 ], was used to calculate the total SFE and its components, namely the dispersive component, also named the Lifshitz–van der Waals interaction, ( ) and polar Lewis acid-base interactions ( ), respectively, see Equation (5).…”
New multifunctional materials containing additives derived from natural resources as powdered rosemary ethanolic extract were obtained by melt mixing and processed in good conditions without degradation and loss of additives. Incorporation of powdered rosemary ethanolic extract (R) into poly(lactic acid) (PLA) improved elongation at break, rheological properties, antibacterial and antioxidant activities, in addition to the biocompatibility. The good accordance between results of the chemiluminescence method and radical scavenging activity determination by chemical method evidenced the increased thermoxidative stability of the PLA biocomposites with respect to neat PLA, with R acting as an antioxidant. PLA/R biocomposites also showed low permeability to gases and migration rates of the bioactive compounds and could be considered as high-performance materials for food packaging. In vitro biocompatibility based on the determination of surface properties demonstrated a good hydrophilicity, better spreading and division of fibroblasts, and increased platelet cohesion. The implantation of PLA/R pellets, was proven to possess a good in vivo biocompatibility, and resulted in similar changes in blood parameters and biochemical responses with the control group, suggesting that these PLA-based materials demonstrate very desirable properties as potential biomaterials, useful in human medicine for tissue engineering, wound management, orthopedic devices, scaffolds, drug delivery systems, etc. Therefore, PLA/R-based materials show promising properties for applications both in food packaging and as bioactive biomaterials.
“…For more details on the method, see references [81,82]. To obtain the components of the surface free energy (SFE) and the total SFE of the polymer films, the CA at equilibrium between the film surface and three pure liquid, twice-distilled water, formamide and methylene iodide (as purchased at maximum obtainable purity), was measured by fitting the drop profile using the Young-Laplace equation [82,83,84,85]. The total and the components of SFE were calculated by using the Lifshitz-van der Waals acid/base approach of van Oss and Good [86], which divides the total SFE into dispersive Lifshitz-van der Waals interactions (γsvLW) and polar Lewis acid-base interactions (γsvAB) (Equation (8)).…”
The purpose of the present study is to develop new multifunctional environmentally friendly materials having applications both in medical and food packaging fields. New poly(lactic acid) (PLA)-based multifunctional materials containing additives derived from natural resources like chitosan (CS) and rosemary extract (R) were obtained by melt mixing. Each of the selected components has its own specific properties such as: PLA is a biodegradable thermoplastic aliphatic polyester derived from renewable biomass, heat-resistant, with mechanical properties close to those of polystyrene and polyethylene terephthalate, and CS offers good antimicrobial activity and biological functions, while R significantly improves antioxidative action necessary in all applications. A synergy of their combination, an optimum choice of their ratio, and processing parameters led to high performance antimicrobial/antioxidant/biocompatible/environmentally degradable materials. The polyethylene glycol (PEG)-plasticized PLA/chitosan/powdered rosemary extract biocomposites of various compositions were characterized in respect to their mechanical and rheological properties, structure by spectroscopy, antioxidant and antimicrobial activities, and in vitro and in vivo biocompatibility. Scanning electron microscopy images evidence the morphology features added by rosemary powder presence in polymeric materials. Incorporation of additives improved elongation at break, antibacterial and antioxidant activity and also biocompatibility. Migration of bioactive components into D1 simulant is slower for PEG-plasticized PLA containing 6 wt % chitosan and 0.5 wt % rosemary extract (PLA/PEG/6CS/0.5 R) biocomposite and it occurred by a diffusion-controlled mechanism. The biocomposites show high hydrophilicity and good in vitro and in vivo biocompatibility. No hematological, biochemical and immunological modifications are induced by subcutaneous implantation of biocomposites. All characteristics of the PEG-plasticized PLA-based biocomposites recommend them as valuable materials for biomedical implants, and as well as for the design of innovative drug delivery systems. Also, the developed biocomposites could be a potential nature-derived active packaging with controlled release of antimicrobial/antioxidant compounds.
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