Investigation of poly(lactic acid) nanocapsules containing the plant extract via coaxial electrospraying method for functional nonwoven applications

This study focuses on the development of functional nanocapsules via the coaxial electrohydrodynamic atomization (electrospraying) method. These nanocapsules can manipulate nonwoven surface functionality in terms of antibacterial characteristics for medical textile purposes. Electrosprayed nanocapsules were produced from Poly(lactic acid) (PLA) polymer and Plumbago europaea plant extract. Here, we employ optimized solution and process parameters (needle to collector distance, electrical field, application time, and needle dimension) for the coaxial electrospraying process. Different Plumbago europaea extract concentrations and co-fluids’ flow rates were investigated as part of the study. Also, the effect of these parameters on capsule morphology and dimension were investigated. After the formation of PLA nanocapsules, morphological and dimensional characteristics were analyzed through SEM, FESEM, TEM images in addition to FTIR and nanosize measurements. According to our findings, a lower co-fluids’ flow rate gives the smaller nanocapsules with narrow-sized distribution and desired spherical morphology. Antibacterial efficiency doesn’t show any significant difference except the lowest plant extract concentrations. After characterizing the nanocapsules’ structures, the core-sheath structure can be clearly identified. Consequently, the desired capsule morphology and size for nanocapsules were accomplished. The antibacterial efficiency of covered surfaces with nanocapsules is up to 80% for Staphylococcus aureus and about 31% for Escherichia coli, even with low pick-up ratios. Even for a very low amount of extract usage, good antibacterial efficiency can be achieved. The application has endless potential in terms of higher concentration and a wide range of chemical usage.

Download Full-text

Toxicity Evaluation of Graphene and Poly(Lactic-Acid) Using a Nematode Model

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.290.101 ◽

2019 ◽

Vol 290 ◽

pp. 101-106

Author(s):

Cin Kong ◽

Azzahraa Izzati Aziz ◽

Akesh Babu Kakarla ◽

Ing Kong ◽

Wei Kong

Keyword(s):

Lactic Acid ◽

Corn Starch ◽

Feeding Activity ◽

Reproductive Rate ◽

Poly Lactic Acid ◽

Mechanical And Thermal Properties ◽

Live Animal ◽

Pumping Rate ◽

C Elegans ◽

Significant Difference

Graphene has gained tremendous attention due to its unlimited potential in various applications while poly(lactic acid) (PLA) is a biodegradable thermoplastic polyester produced from fermenting corn starch. The incorporation of graphene into PLA has been proven to exhibit excellent mechanical and thermal properties. However, there are not many reports on the potential toxic effect of these materials towards living organisms. In this study, we investigated the possible toxicity of graphene and PLA-graphene in a live animal model, the nematode Caenorhabdits elegans (C. elegans). Alive adult worms were exposed directly to graphene and PLA-graphene across a range of concentrations from 50 µg/mL to 1000 µg/mL. After certain hours of exposure, the pharyngeal pumping rate (indicative of the C. elegans feeding activity), reproductive rate and lifespan of the worms were determined and compared to the untreated worm population. At all concentrations tested, both graphene and PLA-graphene do not affect the feeding rate of the nematode. Additionally, there was no significant difference between the lifespan of worms exposed to graphene and PLA-graphene as compared to the untreated control population (p>0.05). We examined the effect of graphene on nematode’s ability to reproduce and no reduction in progenies was detected (p>0.05). Taken together, our findings suggest that graphene and PLA-graphene do not possess a negative effect on the feeding activity, reproduction and overall lifespan of the host, indicating that these materials are safe to living organism at concentration up to 1000 µg/mL.

Download Full-text

Crystallization and Thermal Degradation of Green Nanocomposites Based on Lignin Coated Cellulose Nanocrystals and Poly(Lactic Acid)

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.737.256 ◽

2017 ◽

Vol 737 ◽

pp. 256-261 ◽

Cited By ~ 1

Author(s):

Martin Boruvka ◽

Luboš Bĕhálek

Keyword(s):

Lactic Acid ◽

Cellulose Nanocrystals ◽

Raw Material ◽

Degree Of Crystallinity ◽

Poly Lactic Acid ◽

Crystalline Cellulose ◽

Melt Crystallization ◽

Scanning Calorimetry ◽

Wide Range ◽

Twin Screw

Cellulose is almost inexhaustible source of raw material comprising at least one-third of all biomass matter. Through deconstruction of cellulose hierarchical structure can be extracted highly crystalline cellulose nanocrystals (CNC) with impressive properties. However, the main barrier in the processing of the nanocomposites based on CNC is their inhomogeneous dispersion and distribution in the non-polar polymer matrix. In this paper is this problem addressed by use of novel hydrophobic lignin coated CNC as a biobased nucleation agents in poly (lactic acid) (PLA) nanocomposites. These green nanocomposites based on natural plant derived substances have enormous potential to replace materials originated from non-renewable resources and show promise of providing degradation back into the environment when they are no longer needed. Resulted composites prepared by twin screw extrusion and injection moulding were characterized by means of scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The addition of L-CNC (1, 2 and 3 wt. %) into PLA increased melt crystallization enthalpy and decreases the cold crystallization enthalpy. The degree of crystallinity (cc) increased from 5.6 % (virgin PLA) to 8.5 % (PLA/1-L-CNC), 10.3 % (PLA/2-L-CNC) and 10.7 % (PLA/3-L-CNC). The wide range of degradation temperatures of lignin coating has been observed starting at 100 °C.

Download Full-text

Flexible fibrous membrane based on copper(II) metal-organic framework/poly(lactic acid) composites with superior antibacterial performance

Biomaterials Science ◽

10.1039/d1bm00164g ◽

2021 ◽

Author(s):

Zhao Liu ◽

Junwei Ye ◽

Abdul Rauf ◽

Siqi Zhang ◽

Guangyao Wang ◽

...

Keyword(s):

Lactic Acid ◽

Metal Organic Framework ◽

Three Dimensional ◽

Fibrous Membrane ◽

Poly Lactic Acid ◽

Healthcare Applications ◽

Antibacterial Efficiency ◽

Antibacterial Performance ◽

Metal Organic ◽

Organic Framework

Flexible antibacterial fibrous membrane employing high antibacterial efficiency has great potential in healthcare applications. Herein, a three-dimensional copper(II) metal-organic framework [Cu2(CA)(H2O)2, Cu-MOF-1] and poly(lactic acid) (PLA) composite fibrous membrane was...

Download Full-text

Voltammetric pH Measurements in Unadulterated Foodstuffs, Urine, and Serum with 3D-Printed Graphene/poly(lactic Acid) Electrodes

10.26434/chemrxiv.12698462 ◽

2020 ◽

Author(s):

Fakher M. Rabboh ◽

Glen O'Neil

Keyword(s):

Lactic Acid ◽

Excellent Agreement ◽

Alkali Metals ◽

Reaction Rates ◽

Poly Lactic Acid ◽

Ph Measurements ◽

Wide Range ◽

3D Printed ◽

Glass Ph Electrode ◽

The Impact

The pH of a system is a critical descriptor of its chemistry – impacting reaction rates, solubility, chemical speciation, and homeostasis. As a result, pH is one of the most commonly measured parameters in food safety, clinical, and environmental laboratories. Glass pH probes are the gold standard for pH measurements, but suffer drawbacks including frequent recalibration, wet storage of the glass membrane, difficulty in miniaturization, and interferences from alkali metals. In this work, we describe a voltammetric pH sensor that uses a 3D-printed graphene/poly(lactic acid) filament electrode that is pretreated to introduce quinone functional groups to the graphene surface. After thoroughly characterizing the pretreatment parameters using outer-sphere and inner-sphere redox couples, we measured pH by reducing the surface-bound quinones, which undergo a pH-dependent 2e–/2H+ reduction. The position of the redox peak was found to shift –60 ± 2 mV pH-1 at 25 ºC, which is in excellent agreement with the theoretical value predicted by the Nernst Equation (–59.2 mV pH-1). Importantly, the sensors did not require the removal of dissolved oxygen prior to successful pH measurements. We investigated the impact of common interfering species (Pb2+ and Cu2+) and found that there was no impact on the measured pH. We subsequently challenged the sensors to measure the pH of unadulterated complex samples including cola, vinegar, serum, and urine, and obtained excellent agreement compared to a glass pH electrode. In addition to the positive analytical characteristics, the sensors are extremely cheap and easy to fabricate, making them highly accessible to a wide range of researchers. These results pave the way for customizable pH sensors that can be fabricated in (nearly) any geometry for targeted applications using 3D-printing.

Download Full-text

Analysis of the influence of electrospinning process parameters on the morphology of poly(lactic acid) fibres

Archives of Materials Science and Engineering ◽

10.5604/01.3001.0013.2386 ◽

2019 ◽

Vol 2 (96) ◽

pp. 73-78

Author(s):

W. Matysiak ◽

A. Kapica ◽

T. Tański ◽

A. Dubiel

Keyword(s):

Lactic Acid ◽

Optimal Parameter ◽

Polymeric Materials ◽

Electrospinning Process ◽

Polymer Materials ◽

Poly Lactic Acid ◽

One Dimensional ◽

Wide Range ◽

Spinning Process ◽

Tissue Scaffolding

Purpose: The article focuses on the production of polymer nanofibres from poly(lactic acid) using the electro-spinning method, i.e. the technique of forming fibres in an electrostatic field. The main aim of the publication was to analyse the influence of the distance between electrodes on the morphology of one-dimensional polymeric materials obtained. Design/methodology/approach: In the practical part of the study solutions of polylactide in acetone and a mixture of chloroform/dimethylformamide (DMF) were produced. After 72 hours of mixing, no homogeneous solutions were obtained, therefore a solution consisting of a polylactide dissolved in chloroform was prepared, to which dimethylformamide was added in order to dilute the mixture. The morphology of the nanostructures obtained was analysed by means of a scanning electron microscope (SEM) equipped with an X-ray energy dispersion spectrometer (EDS), which allowed to analyse the chemical composition of the nanofibres produced. The electro-spinning method used to obtain fibres is characterized by high versatility - it gives the possibility to produce fibres from a wide range of polymers. Electro-spinning is also an economic method, and spinned fibres have a wide application potential. Findings: Nanofibres obtained by electro-spinning from the previously produced solution, regardless of the distance between the nozzle and the collector (10 or 20 cm) did not show any significant discrepancies in the values of measured diameters. Fibres obtained at increased distance between electrodes (20 cm) are characterized by a smaller average diameter value, but the difference is small, fluctuating between 48-49 nm. In the case of the sample formed during electro-spinning at the distance of the nozzle - collector equal to 10 cm and the sample produced at the distance doubled, no defects in the structure of the obtained nanofibres were observed. The analysis of topographic images of surfaces produced in the course of nanostructures' work did not show any significant influence of the distance between the nozzle and collector on the diameter of fibres. No defects in the structure of one-dimensional polymer materials obtained allowed to state that the distance between the nozzle and the collector in the range of 10-20 cm is the optimal parameter of the electro-spinning process allowing to obtain smooth, untangled fibres. Practical implications: The fibrous polymer mats obtained during the electro-spinning process of polylactide can be used as protective clothing materials, as drug delivery systems, as tissue scaffolding and as filtration membranes. Originality/value: At present, there are few articles in the literature on the electrospinning process, due to the fact that it is a constantly developing matte for the production of nanofibres. Moreover, most of the research focuses on fibres obtained from nonbiodegradable polymers, which do not have the advantages of fibres obtained from polylactide.

Download Full-text

Fabrication, Characterization, and Cytotoxicity of Thermoplastic Polyurethane/Poly(lactic acid) Material Using Human Adipose Derived Mesenchymal Stromal Stem Cells (hASCs)

Polymers ◽

10.3390/polym10101073 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1073 ◽

Cited By ~ 8

Author(s):

Anna Lis-Bartos ◽

Agnieszka Smieszek ◽

Kinga Frańczyk ◽

Krzysztof Marycz

Keyword(s):

Tissue Engineering ◽

Lactic Acid ◽

Thermoplastic Polyurethane ◽

Tensile Tests ◽

In Vitro Assays ◽

Poly Lactic Acid ◽

Scanning Calorimetry ◽

Casting Technique ◽

Wide Range

Thermoplastic polyurethane (TPU) and poly(lactic acid) are types of biocompatible and degradable synthetic polymers required for biomedical applications. Physically blended (TPU+PLA) tissue engineering matrices were produced via solvent casting technique. The following types of polymer blend were prepared: (TPU+PLA) 7:3, (TPU+PLA) 6:4, (TPU+PLA) 4:6, and (TPU+PLA) 3:7. Various methods were employed to characterize the properties of these polymers: surface properties such as morphology (scanning electron microscopy), wettability (goniometry), and roughness (profilometric analysis). Analyses of hydrophilic and hydrophobic properties, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) of the obtained polymer blends were conducted. Tensile tests demonstrated that the blends exhibited a wide range of mechanical properties. Cytotoxicity of polymers was tested using human multipotent stromal cells derived from adipose tissue (hASC). In vitro assays revealed that (TPU+PLA) 3:7 matrices were the most cytocompatible biomaterials. Cells cultured on (TPU+PLA) 3:7 had proper morphology, growth pattern, and were distinguished by increased proliferative and metabolic activity. Additionally, it appeared that (TPU+PLA) 3:7 biomaterials showed antiapoptotic properties. hASC cultured on these matrices had reduced expression of Bax-α and increased expression of Bcl-2. This study demonstrated the feasibility of producing a biocompatible scaffold form based on (TPU+PLA) blends that have potential to be applied in tissue engineering.

Download Full-text

Properties and Skin Compatibility of Films Based on Poly(Lactic Acid) (PLA) Bionanocomposites Incorporating Chitin Nanofibrils (CN)

Journal of Functional Biomaterials ◽

10.3390/jfb11020021 ◽

2020 ◽

Vol 11 (2) ◽

pp. 21 ◽

Cited By ~ 9

Author(s):

Maria-Beatrice Coltelli ◽

Laura Aliotta ◽

Alessandro Vannozzi ◽

Pierfrancesco Morganti ◽

Luca Panariello ◽

...

Keyword(s):

Lactic Acid ◽

Calcium Carbonate ◽

Chain Scission ◽

Poly Lactic Acid ◽

Butylene Succinate ◽

Agar Diffusion Test ◽

Wide Range ◽

Poly Ethylene ◽

Skin Compatibility ◽

Die Extrusion

Nanobiocomposites suitable for preparing skin compatible films by flat die extrusion were prepared by using plasticized poly(lactic acid) (PLA), poly(butylene succinate-co-adipate) (PBSA), and Chitin nanofibrils as functional filler. Chitin nanofibrils (CNs) were dispersed in the blends thanks to the preparation of pre-nanocomposites containing poly(ethylene glycol). Thanks to the use of a melt strength enhancer (Plastistrength) and calcium carbonate, the processability and thermal properties of bionanocomposites films containing CNs could be tuned in a wide range. Moreover, the resultant films were flexible and highly resistant. The addition of CNs in the presence of starch proved not advantageous because of an extensive chain scission resulting in low values of melt viscosity. The films containing CNs or CNs and calcium carbonate resulted biocompatible and enabled the production of cells defensins, acting as indirect anti-microbial. Nevertheless, tests made with Staphylococcus aureus and Enterobacter spp. (Gram positive and negative respectively) by the qualitative agar diffusion test did not show any direct anti-microbial activity of the films. The results are explained considering the morphology of the film and the different mechanisms of direct and indirect anti-microbial action generated by the nanobiocomposite based films.

Download Full-text

Evaluation of Mechanical and Interfacial Properties of Bio-Composites Based on Poly(Lactic Acid) with Natural Cellulose Fibers

International Journal of Molecular Sciences ◽

10.3390/ijms20040960 ◽

2019 ◽

Vol 20 (4) ◽

pp. 960 ◽

Cited By ~ 21

Author(s):

Laura Aliotta ◽

Vito Gigante ◽

Maria Coltelli ◽

Patrizia Cinelli ◽

Andrea Lazzeri

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Agricultural Waste ◽

Natural Fibers ◽

Analytical Models ◽

Poly Lactic Acid ◽

Polymeric Matrices ◽

Cellulosic Fibers ◽

Natural Cellulose ◽

Wide Range

The circular economy policy and the interest for sustainable material are inducing a constant expansion of the bio-composites market. The opportunity of using natural fibers in bio-based and biodegradable polymeric matrices, derived from industrial and/or agricultural waste, represents a stimulating challenge in the replacement of traditional composites based on fossil sources. The coupling of bioplastics with natural fibers in order to lower costs and promote degradability is one of the primary objectives of research, above all in the packaging and agricultural sectors where large amounts of non-recyclable plastics are generated, inducing a serious problem for plastic disposal and potential accumulation in the environment. Among biopolymers, poly(lactic acid) (PLA) is one of the most used compostable, bio-based polymeric matrices, since it exhibits process ability and mechanical properties compatible with a wide range of applications. In this study, two types of cellulosic fibers were processed with PLA in order to obtain bio-composites with different percentages of microfibers (5%, 10%, 20%). The mechanical properties were evaluated (tensile and impact test), and analytical models were applied in order to estimate the adhesion between matrix and fibers and to predict the material’s stiffness. Understanding these properties is of particular importance in order to be able to tune and project the final characteristics of bio-composites.

Download Full-text

Preparation and Properties of Nanocomposites Based on Poly(Lactic Acid) and Modified TiO2

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.463-464.519 ◽

2012 ◽

Vol 463-464 ◽

pp. 519-522 ◽

Cited By ~ 3

Author(s):

Achanai Buasri ◽

Nattawut Chaiyut ◽

Chanon Kritsanakun ◽

Chettha Phatkun ◽

Tiwiwan Khunsri

Keyword(s):

Lactic Acid ◽

Propionic Acid ◽

Uv Irradiation ◽

Nano Particles ◽

Poly Lactic Acid ◽

Nano Composites ◽

Nano Particle ◽

High Transparency ◽

Wide Range ◽

Ft Ir

In this study, poly (lactic acid) (PLA)-TiO2nano particle nano composites were prepared and the severe aggregation of TiO2nano particles in polymer matrixwere reduced by themodification of TiO2surface with propionic acid and n-hexylamine. The resulting products were characterized by FT-IR, DSCand SEMtechniques so as to have a better understanding of bondingbetween the polymer and nano particles. All of nano composites with a wide range of TiO2additionexhibit the high transparency. SEM micrographs of the nano composites showed of the TiO2nano particles were uniformly dispersed in polymer matrices. Photodegradation of PLA-TiO2nano particle nano composites were also investigated. The results indicated that nano composites could be efficiently photodegraded by UV irradiation in comparison with pure PLA.

Download Full-text

The effect of carbon nanotubes-grafted lactide on the mechanical and thermal properties of poly (lactic acid) biocomposites

Journal of Reinforced Plastics and Composites ◽

10.1177/0731684417696155 ◽

2017 ◽

Vol 36 (9) ◽

pp. 655-666 ◽

Cited By ~ 4

Author(s):

Gaihong Wu ◽

Shuqiang Liu ◽

Xiongying Wu ◽

Xuemei Ding

Keyword(s):

Carbon Nanotubes ◽

Lactic Acid ◽

Thermal Properties ◽

Composite Films ◽

Poly Lactic Acid ◽

Mechanical And Thermal Properties ◽

Wide Range ◽

Ft Ir ◽

The Fourier Transform ◽

Flexible Fabrication

Poly(lactic acid) (PLA) derived from renewable crops is a promising substitute for petroleum-based products. Although PLA exhibits positive features, it also possesses drawbacks, such as brittleness, which hinder its extension in specific applications. In this study, lactide (LA) was used to graft carbon nanotubes (CNTs) to reinforce PLA. Under catalysis, LA was polymerized into PLA through ring-opening polymerization and simultaneously was grafted onto CNTs to obtain CNTs modified by LA (LA/CNTs). And the modified CNTs were used to prepare PLA composite films (LA/CNTs/PLA). Analysis of the Fourier transform infrared spectra (FT-IR) of the modified CNTs indicated that LA was grafted with the nanotubes. The scanning electron microscopy images showed that the modified CNTs were compatible and homogeneously dispersed in the PLA matrix. The excellent dispersibility and compatibility of the CNTs led to good interfacial adhesion, which directly enhanced the mechanical properties of PLA. The addition of CNTs also improved the thermal properties of PLA. This research aims to ameliorate the mechanical and thermal properties of PLA and provides basis for flexible fabrication of bio-based PLA materials for a wide range of applications.

Download Full-text