RESUMO
Chitosan dialdehyde (ChDA) was prepared from a three-step process initiated by thermal organic acid hydrolysis, periodate oxidization, and precipitation from native chitosan (NCh). The developed ChDA resulted in an aldehydic content of about 82 % with increased solubility (89 %) and maximum yield (97 %). The functional alteration of the aldehydic (-CHO) group in ChDA was established using vibrational stretching at 1744 cm-1. The increase in the zone of inhibition of ChDA compared to NCh has confirmed the inherent antimicrobial effect against bacterial and fungal species. ChDA showed better antioxidant activity of about 97.4 % (DPPH) and 31.1 % (ABTS) compared to NCh, measuring 45.3 % (DPPH) and 15.9 % (ABTS), respectively. The novel insilico predictions of the ChDA's biocidal activity were confirmed through molecular docking studies. The amino acid moiety such as ARG 110 (A), ASN 206 (A), SER 208 (A), THR 117 (B), ASN 118 (B), and LYS 198 (B) residues of 7B53 peptide from E. coli represents the binding pockets responsible for interaction with aldehyde group of ChDA. Whereas PHE 115 (E), ALA 127 (H), TYR 119 (C), GLN 125 (H), ASN 175 (E), ARG 116 (E), LYS 101 (H), and LYS 129 (H) of 1IYL A peptide from Candida albicans makes possible for binding with ChDA. Hence, the synergistic effect of ChDA as a biocidal compound is found to be plausible in the drug delivery system for therapeutic applications.
Assuntos
Antioxidantes , Quitosana , Solubilidade , Quitosana/química , Quitosana/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Água/química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Aldeídos/química , Aldeídos/farmacologia , Biopolímeros/química , Biopolímeros/farmacologia , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/síntese química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Fungos/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Simulação por ComputadorRESUMO
Osteoporosis is a prevalent condition characterized by bone loss and decreased skeletal strength, resulting in an elevated risk of fractures. Calcium plays a crucial role in preventing and managing osteoporosis. However, traditional calcium supplements have limited bioavailability, poor solubility, and adverse effects. In this study, we isolated a natural soluble biopolymer, calcium polymalate (PMACa), from the fermentation broth of the fungus Aureobasidium pullulans, to investigate its potential as an anti-osteoporosis therapeutic agent. Characterization revealed that linear PMA-Ca chains juxtaposed to form a porous, rod-like state, in the presence of Ca2+. In vivo mouse models demonstrated that PMA-Ca significantly promoted the conversion of serum calcium into bone calcium, and stimulated bone growth and osteogenesis. Additionally, PMA-Ca alleviated exercise fatigue in mice by facilitating the removal of essential metabolites, such as serum lactate (BLA) and blood urea nitrogen (BUN), from their bloodstream. In vitro studies further showed that PMA-Ca strengthened osteoblast cell activity, proliferation, and mineralization. And PMA-Ca upregulated the expression of some genes involved in osteoblast differentiation, indicating a potential correlation between bone formation and PMACa. These findings indicate that soluble PMA-Ca has the potential to be a novel biopolymer-based calcium supplement with sustainable production sourced from the fermentation industry.
Assuntos
Aureobasidium , Cálcio , Fermentação , Osteoporose , Solubilidade , Animais , Camundongos , Osteoporose/tratamento farmacológico , Osteoporose/metabolismo , Cálcio/metabolismo , Biopolímeros/química , Biopolímeros/farmacologia , Aureobasidium/metabolismo , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteogênese/efeitos dos fármacos , Fadiga/tratamento farmacológico , Água/química , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Diferenciação Celular/efeitos dos fármacosRESUMO
The most likely materials for use in packaging are plastics. A lot of synthetic polymers are harming the environment. A plasticizer is required for all polymers to improve their characteristics and workability. The plasticizers come in liquid form and are also derived from fossil fuels, which are harmful to the environment. Producing functional and affordable biopolymer for packaging applications is a difficult task nowadays. The preparation of biofilm for packaging using biopolymer and bioplasticizer is the main aim of this work. The biopolymer poly L-lactic acid (PLA) is used, and the bio plasticizer is extracted from Pedalium murex plant. Chemical and mechanical methods are used to extract the plasticizer. Plasticization of polylactic acid biopolymer was done using the extracted plasticizer at additions of 1 %, 2 %, 3 %, 4 %, and 5 %. FT-IR spectroscopy, X-ray diffraction spectroscopy, and surface roughness values are used to characterise the prepared biofilms. Scanning electron spectroscopy pictures are utilised to evaluate the morphological orientation of the biofilms. Strawberries packed with biofilms are used to evaluate the barrier properties of biofilms using UV spectroscopy analysis. Thermal degradation behaviour is investigated using thermo gravimetric analysis. We examined the mechanical characteristics, such as tensile strength, elongation modulus, and elongation break percentage. The plasticizing effect of the plasticizer raises the elongation break percentage while decreasing the tensile strength and modulus. For 2 % plasticizer addition the elongation break increases and the tensile not much affected. To demonstrate biodegradability and microbial resistance, the soil degradation behaviour and antimicrobial activities were examined.
Assuntos
Biofilmes , Embalagem de Alimentos , Plastificantes , Poliésteres , Poliésteres/química , Plastificantes/química , Embalagem de Alimentos/métodos , Biofilmes/efeitos dos fármacos , Frutas/química , Biopolímeros/química , Biopolímeros/farmacologia , Resistência à Tração , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Theranostic antibacterial wound dressing is highly recommended in practical applications. The conventional methods of integrating diagnostic and therapeutic functions have the disadvantages of complicated preparation, mutual interference, inability to effectively broad spectrum antibacterial property, and easy to induce drug-resistant bacteria. Herein, a pH and light-responsive theranostic antibacterial hydrogel is developed by biopolymers polyvinyl alcohol (PVA) and polyaniline (PANI), and cross-linking with phytic acid (PA), which is widely present in rice bran. The biological polymer-based conductive hydrogel enables timely diagnosis and photothermal sterilization in-situ for wound healing. Because PANI is highly sensitive to pH changes in the bacterial microenvironment, the hydrogel can detect bacterial infections at concentrations as low as 103 CFU/mL. Subsequently, PANI absorbs near-infrared light to achieve on-demand exothermic sterilization (under 808 nm irradiation for 20 min, the killing ratios for Staphylococcus aureus and Escherichia coli reached almost 100 %). In addition, the hydrogel can monitor the intensity of joint movement to avoid wound re-tearing sensitively. In vitro cytotoxicity and hemocompatibility experiments and in vivo full-thickness infected wound model indicate that the hydrogel has good biocompatibility, antibacterial ability, and can accelerate the wound healing effectively. This work will promote the development of wearable electronic devices and precision medicine.
Assuntos
Antibacterianos , Escherichia coli , Hidrogéis , Oryza , Ácido Fítico , Staphylococcus aureus , Cicatrização , Ácido Fítico/química , Ácido Fítico/farmacologia , Cicatrização/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Hidrogéis/química , Hidrogéis/farmacologia , Oryza/química , Staphylococcus aureus/efeitos dos fármacos , Animais , Escherichia coli/efeitos dos fármacos , Biopolímeros/química , Biopolímeros/farmacologia , Nanomedicina Teranóstica , Camundongos , Humanos , Álcool de Polivinil/química , Compostos de Anilina/química , Compostos de Anilina/farmacologiaRESUMO
AIM: To assess the efficacy of heterologous fibrin biopolymer (HFB) in promoting alveolar bone healing after tooth extraction in rats. MATERIALS AND METHODS: The upper right incisors of 48 Wistar rats were extracted. Toothless sockets were filled with HFB (HFBG, n = 24) or blood clot (BCG, n = 24). The tooth extraction sites were subjected to micro-computed tomography (micro-CT), histological, histomorphometric and immunohistochemical (for Runt-related transcription factor 2/Runx2 and tartrate-resistant acid phosphatase/TRAP) analyses on days 0, 7, 14 and 42 after extraction. RESULTS: Socket volume remained similar between days 0 and 14 (69 ± 5.4 mm3), except in the BCG on day 14, when it was 10% lower (p = .043). Although the number of Runx2+ osteoblasts was high and similar in both groups (34 × 102 cells/mm2), the HFBG showed lower inflammatory process and osteoclast activity than BCG at 7 days. On day 14, the number of Runx2+ osteoblasts remained high and similar to the previous period in both groups. However, osteoclast activity increased. This increase was 55% lower in the HFBG than BCG. In the BCG, the presence of an inflammatory process and larger and numerous osteoclasts on day 14 led to resorption of the alveolar bone ridge and newly formed bone. On day 42, numbers of Runx2+ osteoblast and TRAP+ osteoclasts decreased dramatically in both groups. Although the BCG exhibited a more mature cortical bone formation, it exhibited a higher socket reduction (28.3 ± 6.67%) and smaller bone volume (37 ± 5.8 mm3) compared with HFBG (socket reduction of 14.8 ± 7.14% and total bone volume of 46 ± 5.4 mm3). CONCLUSIONS: HFB effectively suppresses osteoclast activity and reduces alveolar bone resorption compared with blood clot, thus preventing three-dimensional bone loss, particularly during the early healing period. HFB emerges as a promising biopharmaceutical material for enhancing healing processes after tooth extraction.
Assuntos
Fibrina , Ratos Wistar , Extração Dentária , Alvéolo Dental , Cicatrização , Microtomografia por Raio-X , Animais , Alvéolo Dental/efeitos dos fármacos , Ratos , Cicatrização/efeitos dos fármacos , Fibrina/uso terapêutico , Masculino , Biopolímeros/uso terapêutico , Biopolímeros/farmacologia , Processo Alveolar/efeitos dos fármacos , Processo Alveolar/patologia , Processo Alveolar/diagnóstico por imagem , Osteoclastos/efeitos dos fármacosRESUMO
Nanoparticles (NPs) have been extensively investigated for their potential in nanomedicine. There is a significant level of enthusiasm about the potential of NPs to bring out a transformative impact on modern healthcare. NPs can serve as effective wound dressings or delivery vehicles due to their antibacterial and pro-wound-healing properties. Biopolymer-based NPs can be manufactured using various food-grade biopolymers, such as proteins, polysaccharides, and synthetic polymers, each offering distinct properties suitable for different applications which include collagen, polycaprolactone, chitosan, alginate, and polylactic acid, etc. Their biodegradable and biocompatible nature renders them ideal nanomaterials for applications in wound healing. Additionally, the nanofibers containing biopolymer-based NPs have shown excellent anti-bacterial and wound healing activity like silver NPs. These NPs represent a paradigm shift in wound healing therapies, offering targeted and personalized solutions for enhanced tissue regeneration and accelerated wound closure. The current review focuses on biopolymer NPs with their applications in wound healing.
Assuntos
Nanopartículas , Cicatrização , Humanos , Antibacterianos/química , Antibacterianos/farmacologia , Bandagens , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Biopolímeros/química , Biopolímeros/uso terapêutico , Biopolímeros/farmacologia , Quitosana/química , Nanopartículas/química , Cicatrização/efeitos dos fármacosRESUMO
A complex illness with a current global hazard, colon cancer has many different manifestations. The efficacy of colon cancer therapy can be affected by the bacteria in the digestive tract. It is hypothesised that novel prebiotics like Gum Odina is emerging as preventative therapy to fight chronic gut illnesses by gut microbiota modulatory therapy when compared to traditional intervention. The first-line chemotherapy drug for colon cancer, capecitabine, lacks a carrier that can extend its half-life. Here, we use the prebiotic gum odina - sodium alginate conjugate to create a capecitabine loaded biopolymeric microspheres, which were previously established as excellent tools for colon cancer therapy. The accelerated stability study exhibited that the alteration in physicochemical properties was found to be negligible. When administered orally to mice with colon cancer, capecitabine raises intra-tumoral capecitabine concentration and slows drug elimination in the blood. Optimized formulation improves anti-tumor immunity over free capecitabine and decrease the tumor volume from 8⯱â¯6.59â¯mm3 to 5.21⯱â¯2.79â¯mm3. This prebiotics based microsphere combine's gut microbiota manipulation with chemotherapy to offer a potentially effective colon cancer treatment.
Assuntos
Capecitabina , Neoplasias do Colo , Microbioma Gastrointestinal , Microesferas , Prebióticos , Animais , Capecitabina/farmacologia , Camundongos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Microbioma Gastrointestinal/efeitos dos fármacos , Alginatos/química , Alginatos/farmacologia , Biopolímeros/química , Biopolímeros/farmacologia , Portadores de Fármacos/químicaRESUMO
The study reports the efficacy of nanofabricated citronellal inside the chitosan biopolymer (NeCn) against Aspergillus flavus growth, aflatoxin B1 (AFB1) production, and active ingredient biodeterioration (Piperine) in Piper longum L. The prepared NeCn was characterized by Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), and Fourier Transform Infrared Spectroscopy (FTIR). The results revealed that the NeCn exhibited distantly improved antifungal (1.25 µL/mL) and AFB1 inhibition (1.0 µL/mL) compared to free Cn. The perturbances in membrane function, mitochondrial membrane potential, antioxidant defense system, and regulatory genes (Ver-1 and Nor-1) of AFB1 biosynthesis were reported as probable modes of action of NeCn. The NeCn (1.25 µL/mL) effectively protects the P. longum from A. flavus (78.8%), AFB1 contamination (100%), and deterioration of Piperine (62.39%), thus demonstrating its potential as a promising novel antifungal agent for food preservation.
Assuntos
Monoterpenos Acíclicos , Aflatoxina B1 , Aspergillus flavus , Quitosana , Piper , Aflatoxina B1/metabolismo , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/crescimento & desenvolvimento , Aspergillus flavus/metabolismo , Quitosana/química , Quitosana/farmacologia , Piper/química , Biopolímeros/química , Biopolímeros/farmacologia , Monoterpenos Acíclicos/farmacologia , Monoterpenos Acíclicos/química , Aldeídos/farmacologia , Aldeídos/química , Antifúngicos/farmacologia , Antifúngicos/química , Conservação de Alimentos/métodos , Monoterpenos/farmacologia , Monoterpenos/química , Extratos Vegetais/química , Extratos Vegetais/farmacologiaRESUMO
Hemostatic powder is commonly used in emergency bleeding control due to its suitability for irregularly shaped wounds, ease of use, and stable storage. However, traditional powder often has limited tissue adhesion and weak thrombus support, which makes it vulnerable to displacement by blood flow. Herein, we have developed a tricomponent hemostatic powder (MQS) composed of mesoporous bioactive glass nanoparticle (MBG), positively charged quaternized chitosan (QCS), and negatively charged catechol-modified alginate (SADA). Upon application to the wound, MBG with its high specific surface area quickly absorbs plasma, concentrating the blood coagulation factor. Simultaneously, the water-soluble QCS and SADA interact with each other and form a net, which can be further cross-linked by MBG. This network efficiently binds and entraps clustered blood coagulation factors, ultimately resulting in the formation of a durable and robust thrombus. Furthermore, the formed net adheres to the injury site, offering protection against thrombus disruption caused by the bloodstream. Benefiting from the synergistic effect of these three components, MQS demonstrates superior hemostatic performance compared to commercial hemostatic powders like Celox in both arterial injuries and noncompressible liver puncture wounds. Furthermore, MQS can effectively accelerate wound healing. In addition, MQS exhibits excellent antibacterial activity, cytocompatibility, and hemocompatibility. These advantages of MQS, including strong blood clotting, wet tissue adherence, antibacterial activity, wound healing ability, biosafety, ease of use, and stable storage, make it a promising hemostatic agent for emergency situations.
Assuntos
Quitosana , Hemostáticos , Trombose , Humanos , Pós/farmacologia , Hemostasia , Hemostáticos/farmacologia , Cicatrização , Quitosana/farmacologia , Biopolímeros/farmacologia , Antibacterianos/farmacologiaRESUMO
This study investigated the use of nanoemulsions and various polymer coatings to enhance the quality and shelf life of chicken breast. This comprehensive study explored the antibacterial activity of essential oils (EOs) against Escherichia coli and Staphylococcus aureus, as well as the characterization of nanoemulsions (Nes) and nanoemulsion-based coatings. The antimicrobial potential of EOs, such as cinnamon, tea tree, jojoba, thyme, and black cumin seed oil, was evaluated against microorganisms, and thyme oil exhibited the highest inhibitory effect, followed by cinnamon and tea tree oil by disk diffusion analysis. The MIC and MBC values of EOs were found between 0.16-2.5 mg/mL and 0.16-5 mg/mL, respectively, while thyme EO resulted in the lowest values showing its antimicrobial potential. Then, the essential oil nanoemulsions (EONe) and their coatings, formulated with thyme oil, alginate, chitosan, and pectin, were successfully characterized. Optical microscope observations confirmed the uniform distribution of droplets in all (EONe), while particle size analysis demonstrated multimodal droplet size distributions. The EONe-chitosan coating showed the highest efficacy in reducing cooking loss, while the EONe-chitosan, EONe-alginate, and EONe-pectin coatings displayed promising outcomes in preserving color stability. Microbial analysis revealed the significant inhibitory effects of the EONe-chitosan coating against mesophilic bacteria, psychrophilic bacteria, and yeasts, leading to an extended shelf life of chicken breast. These results suggest the potential application of thyme oil and NE-based coatings in various industries for antimicrobial activity and quality preservation.
Assuntos
Anti-Infecciosos , Quitosana , Óleos Voláteis , Óleos de Plantas , Timol , Thymus (Planta) , Animais , Alginatos/farmacologia , Quitosana/farmacologia , Galinhas , Pectinas/farmacologia , Óleos Voláteis/farmacologia , Anti-Infecciosos/farmacologia , Biopolímeros/farmacologia , Escherichia coliRESUMO
Despite the advantages of topical administration in the treatment of skin diseases, current marketed preparations face the challenge of the skin's barrier effect, leading to low therapeutic effectiveness and undesirable side effects. Hence, in recent years the management of skin wounds, the main morbidity-causing complication in hospital environments, and atopic dermatitis, the most common inflammatory skin disease, has become a great concern. Fortunately, new, more effective, and safer treatments are already under development, with chitosan, starch, silk fibroin, agarose, hyaluronic acid, alginate, collagen, and gelatin having been used for the development of nanoparticles, liposomes, niosomes and/or hydrogels to improve the delivery of several molecules for the treatment of these diseases. Biocompatibility, biodegradability, increased viscosity, controlled drug delivery, increased drug retention in the epidermis, and overall mitigation of adverse effects, contribute to an effective treatment, additionally providing intrinsic antimicrobial and wound healing properties. In this review, some of the most recent success cases of biopolymer-based drug delivery systems as part of nanocarriers, semi-solid hydrogel matrices, or both (hybrid systems), for the management of skin wounds and atopic dermatitis, are critically discussed, including composition and in vitro, ex vivo and in vivo characterization, showing the promise of these external drug delivery systems.
Assuntos
Dermatite Atópica , Humanos , Dermatite Atópica/tratamento farmacológico , Cicatrização , Sistemas de Liberação de Medicamentos , Biopolímeros/farmacologia , Colágeno/farmacologia , Hidrogéis/farmacologia , Lipossomos/farmacologiaRESUMO
The expanded uses of bioplastics require understanding the potential health risks associated with their exposure. To address this issue, Drosophila melanogaster as a versatile terrestrial in vivo model was employed, and polylactic acid nanoplastics (PLA-NPLs), as a proxy for bioplastics, were tested as a material model. Effects were determined in larvae exposed for 4 days to different concentrations (25, 100, and 400 µg/mL) of 463.9 ± 129.4 nm PLA-NPLs. Transmission electron microscopy (TEM) and scanning electron microscope (SEM) approaches permitted the detection of PLA-NPLs in the midgut lumen of Drosophila larvae, interacting with symbiotic bacteria. Enzymatic vacuoles were observed as carriers, collecting PLA-NPLs and enabling the crossing of the peritrophic membrane, finally internalizing into enterocytes. Although no toxic effects were observed in egg-to-adult survival, cell uptake of PLA-NPLs causes cytological disturbances and the formation of large vacuoles. The translocation across the intestinal barrier was demonstrated by their presence in the hemolymph. PLA-NPL exposure triggered intestinal damage, oxidative stress, DNA damage, and inflammation responses, as evaluated via a wide set of marker genes. Collectively, these structural and molecular interferences caused by PLA-NPLs generated high levels of oxidative stress and DNA damage in the hemocytes of Drosophila larvae. The observed effects point out the need for further studies aiming to deepen the health risks of bioplastics before adopting their uses as a safe plastic alternative.
Assuntos
Drosophila melanogaster , Drosophila , Animais , Microplásticos/toxicidade , Poliésteres/toxicidade , Biopolímeros/farmacologiaRESUMO
Natural polymers and its mixtures in the form of films, sponges and hydrogels are playing a major role in tissue engineering and regenerative medicine. Hydrogels have been extensively investigated as standalone materials for drug delivery purposes as they enable effective encapsulation and sustained release of drugs. Biopolymers are widely utilised in the fabrication of hydrogels due to their safety, biocompatibility, low toxicity, and regulated breakdown by human enzymes. Among all the biopolymers, polysaccharide-based polymer is well suited to overcome the limitations of traditional wound dressing materials. Pectin is a polysaccharide which can be extracted from different plant sources and is used in various pharmaceutical and biomedical applications including cartilage regeneration. Pectin itself cannot be employed as scaffolds for tissue engineering since it decomposes quickly. This article discusses recent research and developments on pectin polysaccharide, including its types, origins, applications, and potential demands for use in AI-mediated scaffolds. It also covers the materials-design process, strategy for implementation to material selection and fabrication methods for evaluation. Finally, we discuss unmet requirements and current obstacles in the development of optimal materials for wound healing and bone-tissue regeneration, as well as emerging strategies in the field.
Assuntos
Neoplasias , Engenharia Tecidual , Humanos , Engenharia Tecidual/métodos , Pectinas/farmacologia , Neoplasias/tratamento farmacológico , Alicerces Teciduais , Cartilagem , Polissacarídeos/uso terapêutico , Polissacarídeos/farmacologia , Cicatrização , Biopolímeros/farmacologia , Polímeros/farmacologia , Hidrogéis/farmacologia , Materiais Biocompatíveis/farmacologiaRESUMO
Deterioration of perishable foods due to fungal contamination and lipid peroxidation are the most threatened concern to food industry. Different chemical preservatives have been used to overcome these constrains; however their repetitive use has been cautioned owing to their negative impact after consumption. Therefore, attention has been paid to essential oils (EOs) because of their natural origin and proven antifungal and antioxidant activities. Many EO-based formulations have been in use but their industrial-scale application is still limited, possibly due to its poor solubility, vulnerability towards oxidation, and aroma effect on treated foods. In this sense, active food packaging using biopolymers could be considered as promising approach. The biopolymers can enhance the stability and effectiveness of EOs through controlled release, thus minimizes the deterioration of foods caused by fungal pathogens and oxidation without compromising their sensory properties. This review gives a concise appraisal on latest advances in active food packaging, particularly developed from natural polymers (chitosan, cellulose, cyclodextrins etc.), characteristics of biopolymers, and current status of EOs. Then, different packaging and their effectiveness against fungal pathogens, lipid-oxidation, and sensory properties with recent previous works has been discussed. Finally, effort was made to highlights their safety and commercialization aspects towards market solutions.
Assuntos
Quitosana , Filmes Comestíveis , Óleos Voláteis , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Quitosana/farmacologia , Quitosana/química , Conservantes de Alimentos/farmacologia , Conservantes de Alimentos/química , Conservação de Alimentos , Embalagem de Alimentos , Biopolímeros/farmacologiaRESUMO
This work focuses on the preparation of composite beads from alginate crosslinked with copper at several loading percent and also loaded with ZnNPs. Th obtained samples were applied as catalysts for the reduction of the organic polluants 4-NP, MB, OG, MO, and CR in simple and binary systems. XRD results and TEM images confirmed the presence of ZnNPs in the polymer matrix. XRF and TGA analysis showed that the percentage of the cross-linking agent significantly influences the content of ZnNPs as well as the thermal stability of the resulting material. The catalytic activity of the composite beads showed that the Cu(4 %)-ALG(ZnNPs) sample was the best catalyst for all pollutants. In the simple system, the recorded rate constants for MB, MO, 4-NP, OG, and CR were 0.0133 s-1, 0.0076 s-1, 0.005 s-1, 0.0042 s-1, 0.0036 s-1, respectively. The catalyst was more selective towards the cationic MB dye for binary systems. For antibacterial and antifungal applications, the different materials containing ZnNPs and their counterparts containing Zn2+ were found to be active across all bacterial strains (Gram positive and Gram negative) as well as fungi, and the Zn2+-containing composites in particular performed better across all bacteria and fungi.
Assuntos
Nanopartículas Metálicas , Poluentes da Água , Zinco , Porosidade , Antibacterianos/farmacologia , Bactérias , Biopolímeros/farmacologiaRESUMO
Bioplastics arise as an alternative to plastic production delinked from fossil resources. However, as their demand is increasing, there is a need to investigate their environmental fingerprint. Here we study the toxicity of microplastics (MPLs) of two widely used materials, the polylactic acid (PLA) and the polyhydroxybutyrate (PHB) on the environmental aquatic model species Daphnia magna. The study was focused on sublethal behavioural and feeding endpoints linked to antipredator scape responses and food intake. The study aimed to test that MPLs from single-use household comercial items and among them bioplastics should be more toxic than those obtained from standard plastic polymers and fossil plastic materials due to the greater amount of plastic additives, and that MPLs should be more toxic than plastic extracts due to the contribution of both particle and plastic additive toxicity. MPLs were obtained by cryogenic grinding and sea-sand erosion to obtain irregular particles. MPL included standard polymers and nine comercial items of PLA and PHB and one fossil-based material of high-density polyethylene (HDPE). The additive content in commercial items was characterised by liquid chromatography coupled with high-resolution mass spectrometry. D. magna juveniles were exposed for 24 h to particles and their plastic extracts. Results indicated that the toxicity of bioplastic particles was five times higher than the effects produced by exposure to the content of the additives alone, that bioplastic particles were more toxic than fossil ones and that particles obtained from commercial items were more toxic than those obtained from PLA, PHB or HDPE polymer standards. Predicted toxicity from the measured plastic additives in the studied commercially available household items, however, was poorly related with the observed behavioural and feeding effects. Further research on unknown chemical components together with physical factors is need it to fully understand the mechanisms of toxicity of bioplastic materials.
Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Plásticos/toxicidade , Plásticos/análise , Daphnia , Polietileno/farmacologia , Poliésteres/toxicidade , Biopolímeros/farmacologia , Poluentes Químicos da Água/análiseRESUMO
Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent a valuable tool for in vitro modeling of the cardiac niche and possess great potential in tissue engineering applications. However, conventional polystyrene-based cell culture substrates have adverse effects on cardiomyocytes in vitro due to the stress applied by a stiff substrate on contractile cells. Ultra-high viscosity alginates offer a unique versatility as tunable substrates for cardiac cell cultures due to their biocompatibility, flexible biofunctionalization, and stability. In this work, we analyzed the effect of alginate substrates on hPSC-CM maturity and functionality. Alginate substrates in high-throughput compatible culture formats fostered a more mature gene expression and enabled the simultaneous assessment of chronotropic and inotropic effects upon beta-adrenergic stimulation. Furthermore, we produced 3D-printed alginate scaffolds with differing mechanical properties and plated hPSC-CMs on the surface of these to create Heart Patches for tissue engineering applications. These exhibited synchronous macro-contractions in concert with more mature gene expression patterns and extensive intracellular alignment of sarcomeric structures. In conclusion, the combination of biofunctionalized alginates and human cardiomyocytes represents a valuable tool for both in vitro modeling and regenerative medicine, due to its beneficial effects on cardiomyocyte physiology, the possibility to analyze cardiac contractility, and its applicability as Heart Patches.
Assuntos
Células-Tronco Pluripotentes Induzidas , Células-Tronco Pluripotentes , Humanos , Miócitos Cardíacos , Técnicas de Cultura de Células , Biopolímeros/farmacologia , Impressão Tridimensional , Diferenciação CelularRESUMO
Synthesis and fabrication of naturally sourced biopolymers, especially chitosan, grafted with renewable small molecules have recently attracted attention as efficient antimicrobial agents and are highly desired for sustainable material development. Advantageous inherent functionalities in biobased benzoxazine extend the possibility of crosslinking with chitosan which holds immense potential. Herein, a low-temperature, greener facile methodology is adopted for the covalent confinement of benzoxazine monomers bearing aldehyde and disulfide linkages within chitosan to form benzoxazine-grafted-chitosan copolymer films. The association of benzoxazine as Schiff base, hydrogen bonding, and ring-opened structures enabled the exfoliation of chitosan galleries, and such host-guest mediated interactions demonstrated outstanding properties like hydrophobicity, good thermal, and solution stability due to the synergistic effects. Furthermore, the structures empowered excellent bactericidal properties against both E. coli and S. aureus as investigated by GSH loss, live/dead fluorescence microscopy, and morphological alteration on the cell surface by SEM. The work provides the benefits of disulfide-linked benzoxazines on chitosan, offering a promising avenue for general and eco-friendly usage in wound-healing and packaging material.
Assuntos
Anti-Infecciosos , Quitosana , Benzoxazinas/farmacologia , Quitosana/farmacologia , Quitosana/química , Staphylococcus aureus , Escherichia coli , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Biopolímeros/farmacologia , Biopolímeros/químicaRESUMO
Bioplastics derived from organic materials other than crude oil are often suggested as sustainable solutions for tackling end-of-life plastic waste, but little is known of their ecotoxicity to aquatic species. Here, we investigated the ecotoxicity of second and third generation bioplastics toward the freshwater zooplankton Daphnia magna. In acute toxicity tests (48 h), survival was impacted at high concentrations (g.L-1 range), within the range of salinity-induced toxicity. Macroalgae-derived bioplastic induced hormetic responses under chronic exposure (21 d). Most biological traits were enhanced from 0.06 to 0.25 g.L-1 (reproduction rate, body length, width, apical spine, protein concentration), while most of these traits returned to controls level at 0.5 g.L-1. Phenol-oxidase activity, indicative of immune function, was enhanced only at the lowest concentration (0.06 g.L-1). We hypothesise these suggested health benefits were due to assimilation of carbon derived from the macroalgae-based bioplastic as food. Polymer identity was confirmed by infra-red spectroscopy. Chemical analysis of each bioplastic revealed low metal abundance whilst non target exploration of organic compounds revealed trace amounts of phthalates and flame retardants. The macroalgae-bioplastic disintegrated completely in compost and biodegraded up to 86 % in aqueous medium. All bioplastics acidified the test medium. In conclusion, the tested bioplastics were classified as environmentally safe. Nonetheless, a reasonable end-of-life management of these safer-by-design materials is advised to ensure the absence of harmful effects at high concentrations, depending on the receiving environment.
Assuntos
Plásticos , Poluentes Químicos da Água , Animais , Plásticos/química , Polímeros , Biopolímeros/farmacologia , Metais/farmacologia , Testes de Toxicidade Aguda , Daphnia , Poluentes Químicos da Água/toxicidadeRESUMO
The major drawbacks of metal-based implants are weak osseointegration and post-operational infections. These limitations restrict the long-term use of implants that may cause severe tissue damage and replacement of the implant. Recent strategies to enhance the osseointegration process require an elaborate fabrication process and suffer from post-operative complications. To address the current challenges taking inspiration from the extracellular matrix (ECM), the current study is designed to establish enhanced osseointegration with lowered risk of infection. Natural biopolymer pectin, peptide amphiphiles, and enzyme-mimicking fullerene moieties are governed to present an ECM-like environment around the implant surfaces. This multifunctional approach promotes osseointegration via inducing biomineralization and osteoblast differentiation. Application of the biopolymer-based composite to the metal surfaces significantly enhances cellular attachment, supports the mineral deposition, and upregulates osteoblast-specific gene expression. In addition to the osteoinductive properties of the constructed layers, the inherent antimicrobial properties of multilayer coating are also used to prevent infection possibility. The reported biopolymer-artificial enzyme composite demonstrates antimicrobial activity against Escherichia coli and Bacillus subtilis as a multifunctional surface coating.