Epoxidized soybean oil/ZnO biocomposites for soft tissue applications: preparation and characterization

Antimicrobial Efficacy of a Vegetable Oil Plasticizer in PVC Matrices

The growing prevalence of bacterial and viral infections, highlighted by the recent COVID-19 pandemic, urgently calls for new antimicrobial strategies. To this end, we have synthesized and characterized a novel fatty acid epoxy-ester plasticizer for polymers, named GDE. GDE is not only sustainable and user-friendly but also demonstrates superior plasticizing properties, while its epoxy components improve the heat stability of PVC-based matrices. A key feature of GDE is its ability to confer antimicrobial properties to surfaces. Indeed, upon contact, this material can effectively kill enveloped viruses, such as herpes simplex virus type 1 (HSV-1) and the β-coronavirus prototype HCoV-OC43, but it is ineffective against nonenveloped viruses like human adenovirus (HAdV). Further analysis using transmission electron microscopy (TEM) on HSV-1 virions exposed to GDE showed significant structural damage, indicating that GDE can interfere with the viral envelope, potentially causing leakage. Moreover, GDE demonstrates antibacterial activity, albeit to a lesser extent, against notorious pathogens such as Staphylococcus aureus and Escherichia coli. Overall, this newly developed plasticizer shows significant potential as an antimicrobial agent suitable for use in both community and healthcare settings to curb the spread of infections caused by microorganisms contaminating physical surfaces.

Machine Learning for Property Prediction and Optimization of Polymeric Nanocomposites: A State-of-the-Art

Recently, the field of polymer nanocomposites has been an area of high scientific and industrial attention due to noteworthy improvements attained in these materials, arising from the synergetic combination of properties of a polymeric matrix and an organic or inorganic nanomaterial. The enhanced performance of those materials typically involves superior mechanical strength, toughness and stiffness, electrical and thermal conductivity, better flame retardancy and a higher barrier to moisture and gases. Nanocomposites can also display unique design possibilities, which provide exceptional advantages in developing multifunctional materials with desired properties for specific applications. On the other hand, machine learning (ML) has been recognized as a powerful predictive tool for data-driven multi-physical modelling, leading to unprecedented insights and an exploration of the system’s properties beyond the capability of traditional computational and experimental analyses. This article aims to provide a brief overview of the most important findings related to the application of ML for the rational design of polymeric nanocomposites. Prediction, optimization, feature identification and uncertainty quantification are presented along with different ML algorithms used in the field of polymeric nanocomposites for property prediction, and selected examples are discussed. Finally, conclusions and future perspectives are highlighted.

Functional Nanomaterials in Biomedicine: Current Uses and Potential Applications

Nanomaterials, that is, materials made up of individual units between 1 and 100 nanometers, have lately involved a lot of attention since they offer a lot of potential in many fields, including pharmacy and biomedicine, owed to their exceptional physicochemical properties arising from their high surface area and nanoscale size. Smart engineering of nanostructures through appropriate surface or bulk functionalization endows them with multifunctional capabilities, opening up new possibilities in the biomedical field such as biosensing, drug delivery, imaging, medical implants, cancer treatment and tissue engineering. This article highlights up-to-date research in nanomaterials functionalization for biomedical applications. A summary of the different types of nanomaterials and the surface functionalization strategies is provided. Besides, the use of nanomaterials in diagnostic imaging, drug/gene delivery, regenerative medicine, cancer treatment and medical implants is reviewed. Finally, conclusions and future perspectives are provided.

Surface Engineering of Nanomaterials with Polymers, Biomolecules, and Small Ligands for Nanomedicine

Nanomedicine is a speedily growing area of medical research that is focused on developing nanomaterials for the prevention, diagnosis, and treatment of diseases. Nanomaterials with unique physicochemical properties have recently attracted a lot of attention since they offer a lot of potential in biomedical research. Novel generations of engineered nanostructures, also known as designed and functionalized nanomaterials, have opened up new possibilities in the applications of biomedical approaches such as biological imaging, biomolecular sensing, medical devices, drug delivery, and therapy. Polymers, natural biomolecules, or synthetic ligands can interact physically or chemically with nanomaterials to functionalize them for targeted uses. This paper reviews current research in nanotechnology, with a focus on nanomaterial functionalization for medical applications. Firstly, a brief overview of the different types of nanomaterials and the strategies for their surface functionalization is offered. Secondly, different types of functionalized nanomaterials are reviewed. Then, their potential cytotoxicity and cost-effectiveness are discussed. Finally, their use in diverse fields is examined in detail, including cancer treatment, tissue engineering, drug/gene delivery, and medical implants.

Biopolymer Composites: Synthesis, Properties, and Applications

Petroleum-based plastics can be found everywhere in our habitual life in diverse applications such as automobiles, aerospace, and medical science [...].

Polymers and Composites Derived from Castor Oil as Sustainable Materials and Degradable Biomaterials: Current Status and Emerging Trends

Recent years have seen rapid growth in utilizing vegetable oils to derive a wide variety of polymers to replace petroleum-based polymers for minimizing environmental impact. Nonedible castor oil (CO) can be extracted from castor plants that grow easily, even in an arid land. CO is a promising source for developing several polymers such as polyurethanes, polyesters, polyamides, and epoxy-polymers. Several synthesis routes have been developed, and distinct properties of polymers have been studied for industrial applications. Furthermore, fillers and fibers, including nanomaterials, have been incorporated in these polymers for enhancing their physical, thermal, and mechanical properties. This review highlights the development of CO-based polymers and their composites with attractive properties for industrial and biomedical applications. Recent advancements in CO-based polymers and their composites are presented along with a discussion on future opportunities for further developments in diverse applications.

Recent Progress in Antimicrobial Nanomaterials

Bacterial infections are a well-known and serious problem in numerous areas of everyday life, causing death, pain, and huge added costs to healthcare worldwide [...].

Antibacterial Action of Nanoparticle Loaded Nanocomposites Based on Graphene and Its Derivatives: A Mini-Review

Bacterial infections constitute a severe problem in various areas of everyday life, causing pain and death, and adding enormous costs to healthcare worldwide. Besides, they cause important concerns in other industries, such as cloth, food packaging, and biomedicine, among others. Despite the intensive efforts of academics and researchers, there is lack of a general solutions to restrict bacterial growth. Among the various approaches, the use of antibacterial nanomaterials is a very promising way to fight the microorganisms due to their high specific surface area and intrinsic or chemically incorporated antibacterial action. Graphene, a 2D carbon-based ultra-thin biocompatible nanomaterial with excellent mechanical, thermal, and electrical properties, and its derivatives, graphene oxide (GO) and reduced graphene oxide (rGO), are highly suitable candidates for restricting microbial infections. However, the mechanisms of antimicrobial action, their cytotoxicity, and other issues remain unclear. This mini-review provides select examples on the leading advances in the development of antimicrobial nanocomposites incorporating inorganic nanoparticles and graphene or its derivatives, with the aim of providing a better understanding of the antibacterial properties of graphene-based nanomaterials.

Epoxy Coatings Based on Modified Vegetable Oils for Wood Surface Protection against Fungal Degradation

The study describes the curing and thermal behavior of a new castor oil maleic anhydride adduct/epoxy oils/5-Bromosalicylic acid coatings and their composites with wood. The epoxidized oils were flax and hemp. The kinetic parameters of the curing and thermal degradation processes were calculated. The resistance of the coated wood surfaces against Cladosporium cladosporioides, Aspergillus brasiliensis, and Penicillium chrysogenum was tested. Color changes, FT-IR and SEM were conducted before and after fungal attack. The decay resistance and color change of raw wood and wood treated samples against fungi was tested. Based on the color changes and according to ASTM D 2017, the decay resistance rating for covered samples was considered as "highly resistant". Chemical resistance and coating performance tests were also undertaken. The obtained results recommend the described materials for applications in wood protective coatings.

Antibacterial Nanocomposites Based on Thermosetting Polymers Derived from Vegetable Oils and Metal Oxide Nanoparticles

Thermosetting polymers derived from vegetable oils (VOs) exhibit a wide range of outstanding properties that make them suitable for coatings, paints, adhesives, food packaging, and other industrial appliances. In addition, some of them show remarkable antimicrobial activity. Nonetheless, the antibacterial properties of these materials can be significantly improved via incorporation of very small amounts of metal oxide nanoparticles (MO-NPs) such as TiO2, ZnO, CuO, or Fe3O4. The antimicrobial efficiency of these NPs correlates with their structural properties like size, shape, and mainly on their concentration and degree of functionalization. Owing to their nanoscale dimensions, high specific surface area and tailorable surface chemistry, MO-NPs can discriminate bacterial cells from mammalian ones, offering long-term antibacterial action. MO-NPs provoke bacterial toxicity through generation of reactive oxygen species (ROS) that can target physical structures, metabolic paths, as well as DNA synthesis, thereby leading to cell decease. Furthermore, other modes of action-including lipid peroxidation, cell membrane lysis, redox reactions at the NP-cell interface, bacterial phagocytosis, etc.-have been reported. In this work, a brief description of current literature on the antimicrobial effect of VO-based thermosetting polymers incorporating MO-NPs is provided. Specifically, the preparation of the nanocomposites, their morphology, and antibacterial properties are comparatively discussed. A critical analysis of the current state-of-art on these nanomaterials improves our understanding to overcome antibiotic resistance and offers alternatives to struggle bacterial infections in public places.

Synthesis and Applications of Biopolymer Composites

In recent years, there has been a growing demand for a clean and pollution-free environment and an evident target to minimizing fossil fuel [...].

Synthesis, optimization and applications of ZnO/polymer nanocomposites

Polymer composites have established an excellent position among the technologically essential materials because of their wide range of applications. An enormous research interest has been devoted to zinc oxide (ZnO) based polymer nanocomposites, due to their exceptional electrical, optical, thermal, mechanical, catalytic, and biomedical properties. This article provides a review of various polymer composites consisting of ZnO nanoparticles (NPs) as reinforcements, exhibiting excellent properties for applications such as the dielectric, sensing, piezoelectric, electromagnetic shielding, thermal conductivity and energy storage. The preparation methods of such composites including solution blending, in situ polymerization, and melt intercalation are also explained. The current challenges and potential applications of these composites are provided in order to guide future progress on the development of more promising materials. Finally, a detailed summary of the current trends in the field is presented to progressively show the future prospects for the development of ZnO containing polymer nanocomposite materials.

Antimicrobial Coatings Based on Linseed Oil/TiO 2 Nanocomposites

Linseed oil is a cheap, biodegradable, and nontoxic vegetable oil with antimicrobial properties, which has recently attained a lot of interest for the manufacturing of coatings, surfactants, soaps cosmetic products, lubricants, and so forth. Titanium dioxide (TiO₂) is an important semiconductor material frequently employed in foods, cosmetics, paints, coatings, food packaging materials, optical devices, and particularly, antimicrobials due to its strong photocatalytic disinfection ability. This chapter describes the preparation and characterization of acrylated epoxidized linseed oil nanocomposite coatings reinforced with TiO₂ nanoparticles. The effect of TiO₂ loading on the morphology, barrier, thermal, mechanical, tribological, and antibacterial performance of the coatings is summarized. The coatings exhibit antimicrobial activity against gram-negative Escherichia coli and gram-positive Staphylococcus aureus bacteria even in the absence of UV light, and the bactericidal effect increases with the TiO₂ loading. These nanocomposite coatings could be used to prevent microbial proliferation in public places with high risk of infections such as hospitals.

Tissue Engineering Bionanocomposites Based on Poly(propylene fumarate)

Poly(propylene fumarate) (PPF) is a linear and unsaturated copolyester based on fumaric acid that has been widely investigated for tissue engineering applications in recent years due to its tailorable mechanical performance, adjustable biodegradability and exceptional biocompatibility. In order to improve its mechanical properties and spread its range of practical applications, novel approaches need to be developed such as the incorporation of fillers or polymer blending. Thus, PPF-based bionanocomposites reinforced with different amounts of single-walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT), graphene oxide nanoribbons (GONR), graphite oxide nanoplatelets (GONP), polyethylene glycol-functionalized graphene oxide (PEG-GO), polyethylene glycol-grafted boron nitride nanotubes (PEG-g-BNNTs) and hydroxyapatite (HA) nanoparticles were synthesized via sonication and thermal curing, and their morphology, biodegradability, cytotoxicity, thermal, rheological, mechanical and antibacterial properties were investigated. An increase in the level of hydrophilicity, biodegradation rate, stiffness and strength was found upon increasing nanofiller loading. The nanocomposites retained enough rigidity and strength under physiological conditions to provide effective support for bone tissue formation, showed antibacterial activity against Gram-positive and Gram-negative bacteria, and did not induce toxicity on human dermal fibroblasts. These novel biomaterials demonstrate great potential to be used for bone tissue engineering applications.

Antibacterial SnO2 nanorods as efficient fillers of poly(propylene fumarate-co-ethylene glycol) biomaterials

Antibacterial and biocompatible SnO₂ nanorods have been easily synthesized through a hydrothermal process with the aid of a cationic surfactant, and incorporated as nanoreinforcements in poly(propylene fumarate-co-ethylene glycol) (P(PF-co-EG)) copolymer crosslinked with N-vinyl-pyrrolidone (NVP) by sonication and thermal curing. The nanorods were randomly and individually dispersed inside the P(PF-co-EG) network, and noticeably increased the thermal stability, hydrophilicity, degree of crystallinity, protein absorption capability as well as stiffness and strength of the matrix, whilst decreased its level of porosity and biodegradation rate. More importantly, the resulting nanocomposites retained adequate rigidity and strength after immersion in a simulated body fluid (SBF) at 37°C. They also exhibited biocide action against Gram-positive and Gram-negative bacteria; their antibacterial effect was strong under UV-light illumination whilst in dark conditions was only moderate. Further, they did not cause toxicity on human dermal fibroblasts. The friction coefficient and wear rate strongly decreased with increasing nanorod loading under both dry and SBF conditions; the greatest drops in SBF were about 18-fold and 13-fold, respectively, compared to those of the copolymer network. These novel biomaterials are good candidates to be applied in the field of soft-tissue engineering.

Epoxidised soybean oil–Cu/Cu2O bio-nanocomposite material: synthesis and characterization with antibacterial activity

A facile approach for the synthesis of a novel epoxidised soybean oil–Cu/Cu₂O (ESO–Cu/Cu₂O) bio-nanocomposite material via ultrasound irradiation with antibacterial activity was investigated.

Electrospun fibers of chitosan-grafted polycaprolactone/poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) blends

Chitosan-grafted polycaprolactone (CS-g-PCL)/poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHH_x) fiber blends were prepared via wet electrospinning, and their morphology, hydrophilicity, water absorption, biodegradation, cytotoxicity, and thermal, mechanical and antibacterial properties were analyzed. IR spectra revealed strong H-bonding interactions between CS-g-PCL and PHBHH_x. SEM and DSC analysis confirmed the immiscibility of the blends at all compositions studied. As the proportion of CS-g-PCL increased, the overall crystallinity of the blends increased, the melting temperature of PCL decreased, and each component promoted the crystallization of the others. The hydrophilicity, water absorption and weight loss in buffered solution decreased as the PHBHH_x content increased. DMA and tensile tests indicated a synergistic effect on the mechanical properties at a blend composition of 70/30, leading to an optimal combination of stiffness, strength, ductility and toughness. The fibers retained adequate rigidity and strength under physiological conditions. The 70/30 blend exhibited the highest biocide action against Gram-positive and Gram-negative bacteria. The fibers did not induce toxicity over human dermal fibroblasts. These biodegradable, biocompatible electrospun fibers could be used as scaffolds for tissue engineering.

Wound Healing Bionanocomposites Based on Castor Oil Polymeric Films Reinforced with Chitosan-Modified ZnO Nanoparticles

Castor oil (CO), which is a readily available, relatively inexpensive, and environmentally benign nonedible oil, has been successfully used as matrix material to prepare biocompatible and biodegradable nanocomposite films filled with chitosan (CS)-modified ZnO nanoparticles. The biocomposites were synthesized via a simple and versatile solution mixing and casting method. The morphology, structure, thermal stability, water absorption, biodegradability, cytocompatibility, barrier, mechanical, viscoelastic, antibacterial, and wound healing properties of the films have been analyzed. FT-IR spectra were used to obtain information about the nanoparticle-matrix interactions. The thermal stability, hydrophilicity, degree of porosity, water absorption, water vapor transmission rate (WVTR), oxygen permeability (Dk), and biodegradability of the films increased with the CS-ZnO loading. The WVTR and Dk data obtained are within the range of values reported for commercial wound dressings. Tensile tests demonstrated that the nanocomposites displayed a good balance between elasticity, strength, and flexibility under both dry and simulated body fluid (SBF) environments. The flexibility increased in a moist atmosphere due to the plasticization effect of absorbed water. The nanocomposites also exhibited significantly enhanced dynamic mechanical performance (storage modulus and glass transition temperature) than neat CO under different humidity conditions. The antibacterial activity of the films against Escherichia coli, Staphylococcus aureus, and Micrococcus luteus bacteria was investigated in the presence and the absence of UV light. The biocide effect increased progressively with the CS-ZnO content and was systematically stronger against Gram-positive cells. Composites with nanoparticle loading ≤5.0 wt % exhibited very good in vitro cytocompatibility and enabled a faster wound healing than neat CO and control gauze, hence showing great potential to be applied as antibacterial wound dressings.

Development of linseed oil-TiO2 green nanocomposites as antimicrobial coatings

This study deals with the preparation and characterization of acrylated epoxidized linseed oil (AELO) based bionanocomposites for antimicrobial coating applications. AELO was synthesized from epoxidized vegetable oils, crosslinked with an acrylic monomer, reinforced with anatase TiO₂ nanoparticles and then subjected to UV irradiation to yield the cured nanocomposite coatings. The effect of TiO₂ loading on the morphology, barrier, thermal, mechanical, tribological and antibacterial performance of the coatings has been comprehensively investigated. FT-IR spectra indicated the existence of strong TiO₂-AELO hydrogen bonding interactions. The nanoparticles were randomly dispersed within the bioresin, significantly reducing its water absorption and gas permeability whilst increasing its thermal stability. They also promoted remarkable enhancements of both static and dynamic mechanical properties such as storage and Young's moduli, hardness, impact resistance and glass transition temperature. Strong reductions in the coefficient of friction and the wear rate were attained in the nanocomposites with the highest TiO₂ loadings. The coatings were found to display antimicrobial activity even in the absence of UV light, and the bactericidal effect against Staphylococcus aureus was higher than on Escherichia coli. Furthermore, the antimicrobial activity improved with increasing nanoparticle concentration. The use of these "green" nanocomposite coatings could be a suitable and inexpensive method to prevent microbial proliferation in public places, particularly in medical centers where there is higher risk of infections.

Soy protein isolate-based films cross-linked by epoxidized soybean oil

Property enhancement of soy protein isolate-based film was achieved by introducing an environmentally friendly cross-linking agent, epoxidized soybean oil.

WS2 inorganic nanotubes reinforced poly(l-lactic acid)/hydroxyapatite hybrid composite biomaterials

This study confirms the potential use of WS₂ inorganic nanotubes to prepare a novel PLLA/HA hybrid nanocomposite for biomedical applications.