Carbohydrate Polymer Technologies and Applications最新文献

In this study chemical reduction method is used to synthesize the copper and silver nanoparticles. Chitosan was utilized as a stabilizing agent, a suitable medium for nanoparticle growth, and to stop the oxidation and aggregation of the particles. Various characterization such as FTIR Spectra, UV spectra, PL spectra, XRD, EDAX, TEM and Zeta potential approaches were used to examine the copper and silver nanoparticles. The antibacterial activity was assessed through the disc diffusion method. The antibacterial activity to the selected human pathogens, which included two bacterial pathogens such as S. pyogenes and K. pneumoniae as well as one fungal pathogen, Candida albicans . The size and shape of the synthesized CuNPs and AgNPs were evaluated using TEM. The average size distribution is 23.65 nm for CuNPs and 21.76 nm for AgNPs. Copper and AgNPs show antibacterial efficacy against two bacterial strains and a fungi strain. The AgNPs show significant antibacterial activity in comparison with the Chitosan and CuNPs.

The chemistry of chitosan is a promising way to afford biobased and biodegradable complex materials using highly reactive compounds such as anhydrides. However, the potential applications are limited due to the absence of control over the acylation and the lack of precise characterization. After a model study on glucosamine, a selective acylation method of amines or alcohols of chitosan oligomers using anhydrides has been developed. The N-acylation of chitooligosaccharides has been achieved using several anhydrides and the O-acylation has been achieved in three steps: (1) Amine protection using p-anisaldehyde (2) O-acylation (with four anhydrides), and (3) Amine deprotection by removing the protective anisyl groups. Functionalized chitooligosaccharides have been characterized by a precise quantification method using ¹³C nuclear magnetic resonance spectroscopy. The resulting degrees of substitution show in most of the cases a stochiometric reaction between anhydrides and amines of chitooligosaccharides, and around 70 % of efficiency for O-acylation, proving the promising potential of such modifications. To the best of our knowledge, we describe here the first example of selective acylation of chitooligosaccharides using anhydrides, and most of all the first example of ¹³C quantitative NMR spectroscopy performed on chitooligosaccharides and its derivatives. These innovative structures are the gateway to the creation of new biosourced and/or biodegradable surfactants.

Pigment dyeing has gained popularity because it eliminates the need for post-dyeing treatments such as rinsing, neutralization, and washing. Exhaust pigment dyeing demands cotton fiber cationization, often achieved with synthetic agents. This study explores chitosan as a sustainable alternative for cationizing cotton for pigment dyeing. Chitosan has certain advantageous properties that set it apart from synthetic cationic compounds, including biocompatibility and non-toxicity. Cotton fabric was cationized using chitosan at different concentrations and the cationized fabric was subsequently dyed at 3 % shade with pigment using the exhaust method. Cotton dyed with a commercial cationizer served as a comparison. The uniformity of pigment dyeing using chitosan remained unaffected, and comparable K/S values were observed when chitosan replaced the synthetic cationizing agent. Various physical and chemical properties of the dyed fabrics such as color fastness to washing, perspiration (acid and alkali), rubbing fastness, light fastness, stiffness and bursting strength were assessed. Additionally, Fourier Transform-Infrared, Fabric Hand, Biochemical Oxygen Demand, and Chemical Oxygen Demand evaluations were also carried out to examine the viability of using chitosan instead of a synthetic cationizing agent. This study demonstrates chitosan's potential as a sustainable and effective cationizing agent for pigment dyeing.

The natural products contained in Annona muricata leaves are characterized by their ability to effectively enhance the immune response without exhibiting toxicity. The immunomodulatory effect of natural polysaccharides is considered one of the most important bioactive functions. In this study, we investigated the antioxidant activities and immunological properties of heteroglycans extracted from A. muricata leaves using hot water followed by ethanol precipitation. The polysaccharide was characterized for its physicochemical properties (UV spectroscopy, FTIR, gas chromatography), antioxidant potential (scavenging properties, chelating ability, reducing capability, and protection against DNA damage), immunomodulatory activities, and production of pro-inflammatory cytokines using peripheral blood mononuclear cells (PBMCs) and RAW 264.7 cells. The results indicated that the heteroglycans consisted of Glu-Man-GalA-GluA-Xyl and GluA-Man-Glu, respectively, for low and high molecular weight water-soluble polysaccharides coded as LWPC and HWPC. They exhibited strong metal chelating and scavenging activities. Additionally, each sample provided protection against DNA damage induction, with LWPC exhibiting up to 73.1 % protection. LWPC and HWPC significantly down-regulated the expression of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, and COX-2, as well as NO production. At 200 µg/mL, only LWPC increased the production of IL-1β and IL-6 in PBMCs. Therefore, LWPC and HWPC hold promise for inhibiting radical-induced and inflammatory disorders.

Aerogels are renowned for their exceptional characteristics such as high porosity and ultra-low density. Among these, pectin aerogels, offering biodegradability, low toxicity, and versatility, are prominent candidates for innovative biomedical materials. This study focused on synthesizing pectin-based aerogels as carriers for ibuprofen and diclofenac sodium. Hydrogels were formed by combining a low methoxy pectin with calcium chloride solution, followed by dehydration and drying using either supercritical carbon dioxide (scCO₂) or freeze–drying. Comparative analysis showed scCO₂-dried aerogels exhibited slightly less shrinkage (0.27 %) than freeze–dried counterparts. Both types showed high porosity and mesoporous characteristics. However, scCO₂-dried aerogels demonstrated higher specific surface area, pore volume, and smaller pore diameter. FTIR spectra indicated no interaction between the drugs and pectin-based aerogels. The loading of ibuprofen in scCO₂-dried, pectin-based aerogels at 90, 95, and 100 bar were 60.0 %, 59.9 %, and 52.1 %, respectively, and the solution loading of diclofenac sodium was 38.37 %. At 90, 95, and 100 bar, ibuprofen-loaded pectin-based aerogels were released at 90.0 %, 84.0 %, and 75.5 %, respectively. The release of diclofenac sodium-loaded, pectin-based aerogels was at 88.4 %. The Korsmeyer–Peppas model was fitted for both ibuprofen and diclofenac sodium, indicating the release is mainly driven by diffusion.

An easy and cost-effective method has been presented to create a chemosensor AQNC based on the covalent linkage of an anthraquinone (AQ) derivative to nanocellulose (NC) and demonstrates efficient detection capabilities for Hg²⁺, Cr³⁺, and As³⁺ ions. The linkage between AQ and NC to form modified chemosensor AQNC has been confirmed thorough various characterization techniques such as infrared (FTIR), scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). When exposed to Hg²⁺/Cr³⁺/As³⁺ ions, the fluorescence spectrum of AQNC showed fluorescence quenching. This change has been attributed to the ease of the transfer of electrons and/or energy from the fluorophore (AQNC) to the empty d-orbital of the Hg²⁺/Cr³⁺/As³⁺ions that might have facilitated the non-radiative deactivation route, resulting in fluorescence quenching. Thus the successful generation of AQNC will open the imminent of cellulose for waste water remediation.

Considering the nanocomposite structure of natural bone, three-dimensional (3D) nanocomposite hydrogels based on osteoconductive (nano-)materials and polymeric biomaterials are promising scaffolds in bone tissue engineering (TE). Therefore, a novel scaffold composed of chitosan (CS), poly(2-hydroxyethyl methacrylate) (PHEMA), and SiO₂ nanoparticles (NPs) was fabricated for bone TE application. Firstly, SiO₂ NPs were synthesized, and then modified. The modified NPs, CS, and HEMA monomer was copolymerized via free radical polymerization method in the presence of a crosslinker to afford a nanocomposite hydrogel (CS-cl-PHEMA/SiO₂) followed by loading of ciprofloxacin (Cip) as an antibiotic drug. Drug encapsulation efficiency was obtained approximately 20% for the scaffold, and in vitro drug release study revealed that the scaffold had a pH-dependent drug release profile. Applicability of the scaffold in bone TE was examined in terms of numerous physicochemical and biological features. Maximum swelling of scaffold was obtained as 312% after 5 h, and then reached equilibrium. The scaffold exhibited proper in vitro biodegradation, especially in acidic pH. Hemolysis assay revealed that the scaffold was hemocompatible up to 400 µgmL⁻¹ with hemolytic rate of 4.9%. MTT-assay results revealed that the scaffold do not had any toxic effects on the cells and can improve the proliferation of osteoblast cells.

In this review, various aspects of pectins (from raw materials to process-structure-function-applications of this multifunctional biomacromolecule) are discussed taking into consideration the interests of scientists, producers, formulators, including customers and market constraints. Research on pectins has been a subject of interest among many researchers, consequently, numerous articles were published in the past decade. However, there are still some controversial ideas and related challenges associated with this multifunctional polymer which need further clarification. To settle on each of them, the review is structured into four parts: (i) what is already known, (ii) mechanisms describing the physicochemical phenomena involved in pectin techno-functional properties, (iii) current and future challenges from multiple angles, and (iv) related market trends. The information disclosed in this review could be particularly useful for pectin producers allowing them to boost sustainable innovation and also for those seeking in-depth knowledge on different aspects of this versatile biopolymer. Additionally, this review will provide the reader with the tools which allow obtaining fundamental and applied knowledge on pectins.

The current study aimed to design and synthesize a new magnetic nanobiocomposite and assess its potential for biological applications and hyperthermia. For this purpose, in the first step, the Pectin (PC) and Tragacanth gum (TG) polymer was synthesized using CaCl₂ as a cross-linking agent (PC-TG hydrogel). In the second step, natural Silk fibroin (SF) protein and graphitic carbon nitride (CN) were added to the hydrogel to upgrade the nanobiocomposite's strength and due to CN's pharmacology applications, respectively. Finally, for an enhanced hyperthermia application, PC-TG hydrogel/SF/CN was in situ magnetized with Fe₃O₄ magnetic nanoparticles (MNPs), and PC-TG hydrogel/SF/CN/Fe₃O₄ nanobiocomposite was synthesized. By using a vibrating-sample magnetometer (VSM), Fourier-transformed infrared (FTIR), thermogravimetric analysis (TGA), energy dispersive X-ray (EDX), X-ray diffraction (XRD), and field-emission scanning electron microscope (FESEM), the structural features and properties of the PC-TG hydrogel/SF/CN/Fe₃O₄ nanobiocomposite were determined. This magnetic nanobiocomposite's saturation magnetization value was 14.84 emu g^-1. The hemolytic assay of this new nanobiocomposite demonstrated that the hemolysis percentage was 1.07 %, around 99.0 % of cells were able to survive, and the MTT assay was used to assess the anticancer activity against breast cancer cell lines (BT549). Additionally, 62.51 (W g^-1) in 200.0 kHz was found to be the greatest specific absorption rate (SAR). These findings suggest that the recently created magnetic nanobiocomposite might function admirably in hyperthermia treatment when exposed to an alternating magnetic field.

The present study focuses on the utilization of non-conventional starch (NS) derived from guinea grass seed to produce porous starch (PS) and octenyl succinic anhydride-modified PS (OSAPS). The study also introduces a novel approach to produce PS, aiming to overcome the high cost associated with glucoamylase. The formation of porous granules was successfully achieved through the combination of alpha-amylase and ultrasonication, as confirmed by electron micrographs and analysis of pore size and specific surface area. The results demonstrate that OSAPS exhibits superior emulsion stability, well-defined pore structures, and desirable amphiphilic characteristics. All three starches were loaded with lycopene, flaxseed oil, and a combination of both to prepare microcapsules. The presence of flaxseed oil within the starch matrix was confirmed through micrographs and functional group analysis. Notably, OSAPS exhibited the highest encapsulation efficiency at 74.80 %, along with a lycopene retention rate of up to 27.32 mg/100 g. Moreover, OSAPS showcased favorable antioxidant activity (89.29 %), phenolic content (0.45 mg GAE/g), and flavonoid content (97.61 mg QE/100 g). These findings underscore the remarkable potential of OSAPS as a delivery system for bioactive compounds, particularly for the co-encapsulation of oils and pigments.