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1.
Artigo em Inglês | MEDLINE | ID: mdl-38856850

RESUMO

This research paper aims to explore the effect of graphite, wollastonite, and titanium dioxide as reinforcing fillers on starch-based biodegradable plastic (SBP) films. GF-SBP (graphite filler containing SBP), WF-SBP (wollastonite containing SBP), and TF-SBP (titanium dioxide containing SBP) films were developed and analyzed for various properties such as thickness, density, tensile strength, elongation break, morphology, thermal stability, solubility, moisture content, moisture absorbance, biodegradability, and antibacterial activity. The results reveal that WF-SBP films had the highest tensile strength of 5.43 MPa and greatest elongation break value of 22% as compared to other films. Thermogravimetric analysis showed that SBP films with and without filler degraded slowly between 150 and 600°C. The highest thermal stability was recorded for TF-SBP films which showed stability (11% mass loss) up to 150°C. The biodegradability test conducted using soil burial method suggested that TF-SBP film degraded within 90 days, GF-SBP films degraded completely in 120 days, and WF-SBP films took more than 120 days to degrade. The synthesized SBP films were analyzed for their antibacterial potential against gram-positive and gram-negative bacteria, and results showed that WF-SBP film exhibited the best antibacterial activity by producing a large zone of inhibition against Escherichia coli.

2.
PeerJ ; 12: e17328, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38770094

RESUMO

Nanotechnology and nanoparticles have gained massive attention in the scientific community in recent years due to their valuable properties. Among various AgNPs synthesis methods, microbial approaches offer distinct advantages in terms of cost-effectiveness, biocompatibility, and eco-friendliness. In the present research work, investigators have synthesized three different types of silver nanoparticles (AgNPs), namely AgNPs-K, AgNPs-M, and AgNPs-E, by using Klebsiella pneumoniae (MBC34), Micrococcus luteus (MBC23), and Enterobacter aerogenes (MBX6), respectively. The morphological, chemical, and elemental features of the synthesized AgNPs were analyzed by using UV-Vis spectroscopy (UV-Vis), Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy-dispersive spectroscopy (EDX). UV-Vis absorbance peaks were obtained at 475, 428, and 503 nm for AgNPs-K, AgNPs-M, and AgNPs-E, respectively. The XRD analysis confirmed the crystalline nature of the synthesized AgNPs, having peaks at 26.2°, 32.1°, and 47.2°. At the same time, the FTIR showed bands at 599, 963, 1,693, 2,299, 2,891, and 3,780 cm-1 for all the types of AgNPs indicating the presence of bacterial biomolecules with the developed AgNPs. The size and morphology of the AgNPs varied from 10 nm to several microns and exhibited spherical to porous sheets-like structures. The percentage of Ag varied from 37.8% (wt.%) to 61.6%, i.e., highest in AgNPs-K and lowest in AgNPs-M. Furthermore, the synthesized AgNPs exhibited potential for environmental remediation, with AgNPs-M exhibiting the highest removal efficiency (19.24% at 120 min) for methyl orange dye in simulated wastewater. Further, all three types of AgNPs were evaluated for the removal of methyl orange dye from the simulated wastewater, where the highest dye removal percentage was 19.24% at 120 min by AgNPs-M. Antibacterial potential of the synthesized AgNPs assessment against both Gram-positive (GPB) Bacillus subtilis (MBC23), B. cereus (MBC24), and Gram-negative bacteria Enterococcus faecalis (MBP13) revealed promising results, with AgNPs-M, exhibiting the largest zone of inhibition (12 mm) against GPB B. megaterium. Such investigation exhibits the potential of the bacteria for the synthesis of AgNPs with diverse morphology and potential applications in environmental remediation and antibacterial therapy-based synthesis of AgNPs.


Assuntos
Compostos Azo , Nanopartículas Metálicas , Micrococcus luteus , Prata , Prata/química , Prata/farmacologia , Prata/metabolismo , Nanopartículas Metálicas/química , Compostos Azo/química , Compostos Azo/farmacologia , Compostos Azo/metabolismo , Micrococcus luteus/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/metabolismo , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/química , Enterobacter aerogenes/efeitos dos fármacos , Enterobacter aerogenes/metabolismo , Difração de Raios X , Poluentes Químicos da Água/metabolismo , Corantes/química , Corantes/farmacologia
3.
Artigo em Inglês | MEDLINE | ID: mdl-37534485

RESUMO

The temperature-triggered in situ gelling system has been revolutionized by introducing an intelligent polymeric system. Temperature-triggered polymer solutions are initially in a sol state and then undergo a phase transition to form a gel at body temperature due to various parameters like pH, temperature, and so on. These smart polymers offer a number of advantages, including ease of administration, long duration of release of the drug, low administration frequency with good patient compliance, and targeted drug delivery with fewer adverse effects. Polymers such as poly(N-isopropylacrylamide) (PNIPAAm), polyethylene glycol (PEG), poly (N, N'-diethyl acrylamide), and polyoxypropylene (PPO) have been briefly discussed. In addition to various novel Drug Delivery Systems (DDS), the smart temperature-triggered polymeric system has various applications in cancer therapy and many other disease conditions. This review focuses on the principals involved in situ gelling systems using various temperature-triggered polymers for chemotherapeutic purposes, using smart DDS, and their advanced application in cancer therapy, as well as available marketed formulations and recent advances in these thermoresponsive sol-gel transforming systems.

4.
Qual Life Res ; 32(10): 2911-2924, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37289356

RESUMO

INTRODUCTION: Australia's population is steadily growing older, with older persons expected to make up over 20% of the population by 2066. Ageing is strongly associated with a significant drop in cognitive ability, ranging from mild cognitive impairment to severe cognitive impairment (dementia). This study examined the association between cognitive impairment and health-related quality of life (HRQoL) in older Australians. METHODS: Two waves of longitudinal data from the nationally representative Household, Income and Labour Dynamics in Australia (HILDA) survey were utilised, with the age cut-off for older Australians defined as above 50. The final analysis included 10,737 person-year observations from 6892 unique individuals between 2012 and 2016. This study utilised the Backwards Digit Span (BDS) test and Symbol Digit Modalities test (SDMT) to assess cognitive function. HRQoL was measured using the physical and mental component summary scores of the SF-36 Health Survey (PCS and MCS). Additionally, HRQoL was measured using health state utility values (SF-6D score). A longitudinal random-effects GLS regression model was used to analyse the association between cognitive impairment and HRQoL. RESULTS: This study found that approximately 89% of Australian adults aged 50 or older had no cognitive impairment, 10.16% had moderate cognitive impairment, and 0.72% had severe cognitive impairment. This study also found that moderate and severe cognitive impairment were both negatively associated with HRQoL. Older Australians with moderate cognitive impairment scored worse on the PCS (ß = - 1.765, SE = 0.317), MCS (ß = - 1.612, SE = 0.326), and SF-6D (ß = - 0.024, SE = 0.004) than peers without cognitive impairment given other covariates reference categories remain constant. Older adults experiencing severe cognitive had lower PCS (ß = - 3.560, SE = 1.103), and SF-6D (ß = - 0.034, SE = 0.012) scores compared to their counterparts with no cognitive impairment given other covariates reference categories remain constant. CONCLUSION: We found evidence that HRQoL is negatively associated with cognitive impairment. Our findings will be beneficial for the future cost-effectiveness intervention targeted at reducing cognitive impairment since it provides information on the disutility associated with moderate and severe cognitive impairment.


Assuntos
Disfunção Cognitiva , Qualidade de Vida , Humanos , Idoso , Idoso de 80 Anos ou mais , Qualidade de Vida/psicologia , Austrália/epidemiologia , Envelhecimento , Inquéritos e Questionários , Disfunção Cognitiva/epidemiologia
5.
Mini Rev Med Chem ; 22(13): 1735-1751, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35114919

RESUMO

Every day, new cases of cancer patients whose recovery is delayed by multidrug resistance and chemotherapy side effects are identified, which severely limit treatment options. One of the most recent advances in nanotechnology is the effective usage of nanotechnology as drug carriers for cancer therapy. As a consequence, heterocyclic nanocarriers were put into practice to see whether they could have a better cure with positive results. The potential of a therapeutic agent to meet its desired goal is vital to its success in treating any disease. Heterocyclic moieties are molecules that have a wide variety of chemically therapeutic functions as well as a significant biological activity profile. Heterocyclic nanoformulations play an important role in cell physiology and as possible arbitrators for typical biological reactions, making them valuable in cancer research. As a result, experts are working with heterocyclic nanoformulation to discover alternative approaches to treat cancer. Due to their unique physicochemical properties, heterocyclic compounds are real cornerstones in medicinal chemistry and promising compounds for the future drug delivery system. This review briefly explores the therapeutic relevance of heterocyclic compounds in cancer treatment, various nanoformulation, and actively describes heterocyclic magnetic nano catalysts and heterocyclic moiety, as well as their mode of action, which have favorable anti-cancer effects.


Assuntos
Antineoplásicos , Compostos Heterocíclicos , Nanopartículas , Neoplasias , Antineoplásicos/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Compostos Heterocíclicos/uso terapêutico , Humanos , Nanopartículas/química , Nanotecnologia , Neoplasias/tratamento farmacológico
6.
Chemistry ; 26(19): 4304-4309, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31960517

RESUMO

Due to their equivalent lengths, δ-amino acids can serve as surrogates of α-dipeptides. However, δ-amino acids with proteinogenic side chains have not been well studied because of synthetic difficulties and because of their insolubility in organic solvents. Recently we reported the spontaneous supramolecular gelation of δ-peptides composed of ß(O)-δ5 -amino acids. Here, we report the incorporation of ß(O)-δ5 -amino acids as guests into the host α-helix, α,γ-hybrid peptide 12-helix and their single-crystal conformations. In addition, we studied the solution conformations of hybrid peptides composed of 1:1 alternating α and ß(O)-δ5 -amino acids. In contrast to the control α-helix structures, the crystal structure of peptides with ß(O)-δ5 -amino acids exhibit α-helical conformations consisting of both 13- and 10-membered H-bonds. The α,δ-hybrid peptide adopted mixed 13/11-helix conformation in solution with alternating H-bond directionality. Crystal-structure analysis revealed that the α,γ4 -hybrid peptide accommodated the guest ß(O)-δ5 -amino acid without significant deviation to the overall helix folding. The results reported here emphasize that ß(O)-δ5 -amino acids with proteinogenic side chains can be accommodated into regular α-helix or 12-helix as guests without much deviation of the overall helix folding of the peptides.


Assuntos
Aminoácidos/química , Dipeptídeos/química , Peptídeos/química , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares
7.
Biomacromolecules ; 20(3): 1254-1262, 2019 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-30753058

RESUMO

The ordered supramolecular assemblies of short peptides have been recently gaining momentum due to their widespread applications in biology and materials sciences. In contrast to the α-peptides, limited success has been achieved from the backbone modified peptides. The proteolytic stability and conformational flexibility of the backbone modified peptides composed of ß-, γ-, and δ-amino acids can be explored to design ordered supramolecular gels and self-assembled materials. In this article, we are reporting the divergent supramolecular gels from a new class of short hybrid dipeptides composed of conformationally flexible new ß(O)-δ5-amino acids. The hybrid dipeptide composed of ß3- and ß(O)-δ5-Phe showed the formation of transparent gels from the aromatic solvents, while the dipeptide composed of ß(O)-δ5-Phe showed the thixotropic gel in phosphate buffered saline (PBS). In contrast, no organic or hydrogels were observed from the dipeptides composed of alternating α- and ß(O)-δ5-Phe as well as γ4 and ß(O)-δ5-Phe. The organogelation property displayed by the ß3,ß(O)-δ5-Phe dipeptide was further explored to recover the oil spills from the oil-water mixture. The thixotropic hydrogels displayed by the ß(O)-δ5, ß(O)-δ5-Phe dipeptide was further utilized as matrix along with cell culture medium to grow the cells in 2D-cell culture. Replacing the backbone -CH2- with "O" in the δ-Phe leads to the drastic change in the supramolecular behavior of δ-peptides. Overall, the short dipeptides from different backbone modified amino acids showed the divergent gelation properties and these properties can be further explored to design new functional biomaterials.


Assuntos
Hidrogéis/química , Peptídeos/química , Conformação Molecular , Proteólise
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