Physicochemical Characteristics Research Articles

UM FILME DE POLIURETANO DE BASE AQUOSA CONTENDO ÓLEO DE MAMONA E NANOPARTÍCULAS DE PRATA INDUZIU A INIBIÇÃO DE BIOFILME BACTERIANO IN VITRO

Healthcare-related infections (HAIs) are a huge global issue. In 2020, about 11,124 patients (12.7%) with an ICU (intensive care unit) stay of over two days developed at least one ICU-acquired healthcare-associated infection (European Centre for Disease Prevention and Control, 2024). Hospital-acquired infections are mainly caused by contamination of these facilities, which often involves the transmission of microorganisms through contact with contaminated surfaces. In this context, the advancement of novel strategies to mitigate the contamination of medical devices, biomaterials, and hospital equipment is crucial and drives the demand for advancements in materials sciences. The application of antimicrobial polymers to coat medical devices and other hospital equipment has emerged as a promising approach, reducing the risk of healthcare-related contamination. The main goal of this research was to incorporate silver nanoparticles (Ag-NPs) into a waterborne castor oil-based polyurethane (PU) suspension to produce a film coating and evaluate its effectiveness in preventing bacterial adhesion. The films of pristine polyurethane (WBPU) and polyurethane containing Ag-NPs were subjected to physicochemical characterization and antimicrobial assays. Thermogravimetric analysis showed that no decomposition occurs below 200 oC, and the PU can be used in materials at the body temperature range. The WBPU film with 0.4% (w/w) Ag-NPs exhibited 36.4% inhibition of Staphylococcus aureus adhesion and 20.5% inhibition of biofilm formation. This castor oil-based polyurethane antimicrobial film is a promising alternative for coating the surfaces of equipment and devices used in the healthcare sector.

Physicochemical characterization of the brown pigment produced by Azospirillum brasilense HM053 using tryptophan as precursor.

Microorganisms are known to be a promising source of biopigments because they are easy to obtain, can be produced on a commercial scale, and are environmentally friendly. Therefore, the aim of this work was to characterize a brown pigment (BP) produced by HM053 in NFbHPN-lactate medium. The BP was extracted from the pellet (BPP) or supernatant (BPS), in the presence (BPPTrp, BPSTrp) or absence (BPPw, BPSw) of tryptophan (Trp). The UV-vis results were similar among all BP samples and compared with commercial melanin used as a standard, and the maximum absorption was observed around 200-220nm. FTIR spectra showed that BP and commercial melanin had slight differences, with a small band between 3000-2840cm- 1, related to C-H in the CH2 and CH3 aliphatic groups, which is not observed in the commercial melanin. Between BPP and BPS showed a different structure with bands in the region 1230-1070cm- 1 related to groups C-O. The thermogravimetric curves for BPSw and BPSTrp showed similar behavior, with 4 stages of mass loss. The similarity between BPPw and BPPTrp with 2 stages of mass loss was also observed. Scanning electron microscopy results showed morphological differences between BPP and BPS, where BPP had a physical structure more homogeneous and a regular flat surface, while the BPS physical structure did not seem homogeneous and the surface was uneven with some spherical structures as commercial melanin.

A green method to improve adsorption capacity of hydrochar by ball-milling: enhanced norfloxacin adsorption performance and mechanistic insight

The application of hydrochar as a cost-effective solution has received much attention for the remediation of contaminated water. An economical and environmental approach to enhancing the physicochemical and adsorption performance of hydrochar is essential. In this study, the green technology of ball-milling was firstly employed to improve the adsorption capacity of hydrochar for the typical antibiotics norfloxacin. Aqueous batch adsorption experiment using both pristine and ball milled hydrochar derived from water hyacinth, prepared by hydrothermal carbonization at three temperatures (180, 200, 220 °C) was conducted. The results showed that ball-milling decreased the specific surface area of hydrochar, but still greatly enhanced their performance on the adsorption of norfloxacin. Surface functional groups, aromatization degree, and hydrophobicity of hydrochar were increased after ball-milling, as evidenced by measurements of Boehm titration, Raman spectra, and contact angle, respectively. With these changes, all the ball-milled water hyacinth hydrochar exhibited a better performance on the adsorption of norfloxacin than pristine hydrochar. Ball-milled 220 °C water hyacinth hydrochar showed the greatest norfloxacin adsorption (68.53 mg g−1) compared to unmilled hydrochar (24.29 mg g−1), and the enhancement was effective in a wide pH range (5–9) in aqueous solutions. The thermodynamics study indicated that the norfloxacin adsorption on ball-milled hydrochar was both physically spontaneous and exothermic. Combined physicochemical characterization of hydrochar and batch experiment results suggest that the enhanced adsorption capacity was owing to boosting H-bonds, π-π electron-donor–acceptor, and hydrophobic interaction. This study suggested that ball-milling can be served as a facile, green, and cost-effective method to obtain modified hydrochar for the removal of pollutants in water.

Hybrid nanocomposites of Fe3O4/SiO2-EDTA: Holistic comparison of one-step and two-step modification methods

Fe3O4/SiO2-EDTA materials have been used for diverse applications and they have been modification by different methods, but a comparison is lacking between their physicochemical characteristics. This work aimed to compare the physicochemical characteristics of the Fe3O4/SiO2-EDTA nanocomposite obtained by four methods, whose modification of the Fe3O4 surface with SiO2-EDTA occurs in one or two steps, with not hazardous chemicals. In the one-step methods (M1 and M2), Fe3O4 particles were coated and functionalized in consecutive steps (by sonication in M1 and mechanical stirring in M2). In the two-step methods (M3 and M4), the Fe3O4 particles were primarily coated with silica and then functionalized with TMS-EDTA (by sonication in M3 and mechanical stirring in M4). The Fe3O4/SiO2-EDTA nanocomposites were characterized by XRD, TEM, EDX, BET, SQUID magnetometry, FTIR, XPS, and zeta potential. The TEM highlighted that the nanocomposites from methods M1 and M2 there is the simultaneous presence of magnetite particles coated and uncoated with silica, while those from M3 and M4 were totally coated, besides the nanocomposites from M2 and M3 showed to be more aggregated than those from the other methods. The presence of EDTA on the surface of the nanocomposites was evidenced by the carboxyl groups in the FTIR spectra and by the nitrogen in the XPS spectra. The nanocomposites from M3 and M4 presented a higher content of nitrogen than those from M1 and M2, and those from M4 also presented a higher content of carbon than those from M3. Overall, the Fe3O4/SiO2-EDTA nanocomposites from two-step methods showed better SiO2 coating and EDTA functionalization than those from one-step methods, and those from M4 presented the best physicochemical characteristics, being this method recommended for their modification for future applications.

Downflow and upflow sand filtration for removing turbid particles with diverse morphological and surface-charge characteristics: Comparisons of filtered water quality and head loss distribution

Besides the physicochemical characteristics (e.g., size, structure, charge nature, etc.) of turbid particles, the filtration flow direction may affect their migration and adhesion behaviors inside the filtration unit. Unfortunately, there has been a lack of research regarding the combined effects of these above factors on filtered water quality and head loss development during filtration. In this study, different turbid particles were prepared by flocculating water samples containing kaolin and humic acid. Filtration experimental results of these flocculated waters revealed that downflow and upflow filtration modes had different durations of effective filtration under identical PAC-dosage cases, and upflow filtration led to faster increases in filtered water turbidity at the breakthrough stage compared to downflow filtration. During 180-min downflow filtration, the average size of residual turbid particles increased, but this did not occur in upflow filtration. Furthermore, differently from downflow filtration, upflow filtration had a more uniform distribution of head loss across all filter layers. The ease of backwashing differed between the two filtration modes, reflected by the different times required for reaching a relatively stable turbidity during 10-min backwashing. Lastly, based on SEM, FTIR and XPS analyses for characterizing the coagulated particle surface morphology, element composition, and functional groups, a series of conceptual models for particle removal by downflow and upflow filtrations were developed to clarify the influencing mechanisms of different turbid particles on filtration. It highlighted the advantages of upflow filtration, including improved distribution of flow resistance, better removal of larger-sized turbid particles, and enhanced pollutant-holding capacity of the filter media.

Newly developed polymer nanocomposite of chitosan-citrate/ZrO2 nanoparticles for safranin O dye adsorption: Physiochemical properties and response surface methodology

In this work, crosslinked chitosan-citrate/ZrO2 (CS-CIT/ZrO2) nanocomposite was straightforwardly synthesized in two steps: first, chitosan biopolymer (CS) was functionalized with a zirconia inorganic nanomaterial (zirconium dioxide, ZrO2), and then, citrate (CIT) was used in an ionic cross-linking procedure. This new nanocomposite's physicochemical characteristics have been fully investigated using methods including FTIR, CHN–O, BET, pHpzc, XRD, and FESEM-EDX. Using the response surface methodology approach, the removal of cationic dye (Safranin O, SO) from an aqueous solution by CS-CIT/ZrO2 was thoroughly investigated with concerning adsorption factors (pH (4–10), duration (10–90 min), and CS-CIT/ZrO2 dosage (0.02–0.08 g)). Freundlich isotherm demonstrates the equilibrium behavior of SO by CS-CIT/ZrO2. The optimal conditions for achieving the maximum removal of SO (70.7 %) were found to be at pH 10.0, with a dosage of CS-CIT/ZrO2 of 0.05 g/L, and a time of 90 min, depending on the desirability function. A pseudo-first-order model characterized the kinetics data of SO adsorption by CS-CIT/ZrO2 in an adequate manner. CS-CIT/ZrO2 has a remarkable adsorption capacity of 280.14 mg/g. The effective adsorption of SO on the positively charged CS-CIT/ZrO2 is responsible for the electrostatic interactions between the SO cation and the negatively charged CS-CIT/ZrO2, along with the H-bond and n-π interactions. According to this work, CS-CIT/ZrO2 has great promise as a superior bioadsorbent for adsorption of synthesized cationic dyes from polluted water.

A Review on Nanostructured Lipid Carriers as Promising Drug Delivery Vehicle to Target Various Cancers via Oral Route: A Step towards “Chemotherapy at Home”

Abstract: Oral drug administration is largely preferred owing to enhanced patient compliance, convenience of self-intake of dose, non-invasiveness, and low manufacturing cost. Cancer is a condition that starts with aberrant cell division at an uncontrolled rate. The clinical effectiveness of many anticancer drugs is limited by their physicochemical characteristics and physiological circumstances in the GI tract. Nanostructured lipid carriers have the potential to enhance the bio-availability of anticancer drugs by entrapping them. The NLCs, by virtue of their nanosize and their biocompatibility, can bypass the first-pass metabolism and be taken up by M cells of Peyer’s patches to deliver the drug to the deeper tumours. The proposed review highlights the potential of NLCs in oral drug delivery for the management of various cancers. It discusses various strategies, method of preparation, mechanism of uptake, and their applications in the treatment of cancer via oral delivery. Further, it explains the recent advances and future perspectives.

Optimizing dry-air preheating conditions for enhancing bioactive constituents, stability, and physiochemical attributes of niger [Guizotia abyssinica (Lf) Cass.] seed oil

The study employed dry-air preheating (DAP) at different temperatures (140 °C, 160 °C, and 180 °C) and exposure times (5, 10, and 15min) to improve niger seed oil (NiO) qualitative attributes. The changes in physicochemical characteristics, tocopherols, pigments, phytosterols, phenolic acids, flavonoids, and Maillard products in NiO were explored after DAP of niger seeds. The structural changes induced by DAP promoted the release of beneficial components and restrained the development of harmful oxidative products. The NiO yield and oxidative stability index increased from 32.94 to 41.64% and 2.71 to 5.17h upon DAP at 160 °C and 180 °C for 10min, respectively. The total flavonoids (140.58mg/kg), hydroxycinnamic (36.39mg/kg), and hydroxybenzoic (2.724mg/kg) acids were highest upon DAP at 180 °C for 10min, while the browning index (0.130), 5-hydroxymethylfurfural (3.089mg/kg), carotenoids (1.023mg/kg), and viscosity (61.33 mPa·s) were highest upon DAP at 180 °C for 15min. The tocopherols and phytosterols were augmented in NiO upon DAP at 140 °C for 10min, while they were declined by further elevating temperature (180 °C) and exposure time (15min). The results suggest the potential industrial application of DAP for enhancing NiO quality characteristics.

Investigating alterations of nutritional constituents, antioxidant abilities, and physicochemicals in aging processes of ginseng sprouts

This study was the first to document the fluctuations of nutritional constituents, antioxidant capacities, and physicochemical characteristics during the aging processes of red ginseng sprouts (RGS) and black ginseng sprouts (BGS) from dried ginseng sprouts (DGS). Total ginsenoside levels differed with 54.72 (DGS) → 57.15 (RGS) and 6.98 (BGS) mg/g, specifically, ginsenoside F2 and Rd2 in RGS remarkably increased with 1.97 → 5.88 and 2.41 → 5.49 mg/g, respectively. Phenolics increased dramatically as 297.02 → 1770.01 (6.0-fold); 1834.94 (6.2-fold) μg/g in DGS → RGS; BGS with abundance contents of benzoic acid (>15.3-fold), chlorogenic acid (>9.5-fold), and catechin (>4.2-fold), whereas amino acids markedly decreased (3686.81 → 1505.00; 364.64 mg/100 g), with arginine showing a significant decrease. Moreover, beneficial factors (total phenolic content: TPC; total flavonoid content: TFC; maillard reaction products: MRP) displayed increase tendencies (approximately 2.0-fold) with BGS > RGS > DGS, and antioxidant patterns significantly increased with potential capacities as follows: ABTS (48.3: DGS → 65.8: RGS; 70.2 %: BGS) > DPPH (18.5 → 44.6; 59.2 %) > hydroxyl (23.2 → 35.4; 39.9 %) > FRAP (0.6 → 1.8; 1.8 %) at 500 μg/mL. In particular, DNA protection exhibited excellent rates of 100 %, in the order of BGS (25 μg/mL) > RGS (50 μg/mL) > DGS (500 μg/mL). These findings suggest that processed ginseng sprouts can be excellent agents for natural antioxidants.

Physicochemical characteristics and microbial diversity of sous vide scallops (Chlamys farreri) during chilled storage

This study investigated the impact of sous vide (SV) cooking methods on the physical and chemical characteristics as well as the microbial composition of scallops (Chlamys farreri) over a 30 days period of refrigerated storage. Scallop treatments were divided into two groups: CS (scallops vacuum-packed and then steamed for 30 min at 75 °C) and CK (scallops steamed for 15 min at 100 °C). With the increase in refrigeration time, the total volatile basic nitrogen (TVBN), pH, cooking loss, microbial content, and malondialdehyde (MDA) content gradually increased, while the water-soluble protein extraction rate and the myofibrillar protein (MP) extraction rate of the CS and CK samples significantly decreased. Notably, the SV steaming treatment effectively reduced microbial degradation of proteins, improved water retention of scallop samples, and maintained high MP extraction as compared to CK samples (MP content ranged from 1.09% to 2.50% in the CK group and 1.75%–3.33% in the CS group). During the late stages of refrigeration, conventionally cooked scallops (CK) were dominated by Pseudomonas and Psychrobacter, with the ability to produce biogenic amines, while SV steamed scallops were dominated by Psychrobacillus. Furthermore, a link was discovered between the microbial community and the physicochemical parameters.

Effects of industrial-scale pickling processes on the dynamic changes in the physicochemical indicators and microbial diversities of Yacai

The effects of dry-salted and salt-fermented processing on the physicochemical characteristics and microbial communities of Yacai were systematically investigated. The results showed that the contents of total acid, amino acid nitrogen (AAN) and nitrite in the final products of dry-salted Yacai were greater than those in salt-fermented Yacai. Lactic acid was the dominant organic acid in the two types of Yacai. Dry-salted processing is more conducive to forming a high-quality reddish-brown color. During whole pickling process, the microbial diversity of dry-salted Yacai was higher than that of salt-fermented Yacai, particularly in the early and middle stages of fermentation. For dry-salted Yacai, 8 bacteria (Natribacillus, Chromohalobacter, Marinococcus, Lentibacillus, Nesterenkonia, Gracilibacillus, Oceanobacillus and Tetragenococcus) and 1 fungus (Zygosaccharomyces) showed a significant positive correlation with AAN. For salt-fermented Yacai, 8 bacteria (Gracilibacillus, Alkalibacillus, Oceanobacillus, Virgibacillus, Lentibacillus, Salibacterium, Chromohalobacter and Tetragenococcus) and 3 fungi (Zygosaccharomyces, Millerozyma, and Wickerhamomyces) exhibited significant positive correlations with AAN.

Reduction of Beany Flavor and Improvement of Nutritional Quality in Fermented Pea Milk: Based on Novel Bifidobacterium animalis subsp. lactis 80.

Peas (Pisum sativum L.) serve as a significant source of plant-based protein, garnering consumer attention due to their high nutritional value and non-GMO modified nature; however, the beany flavor limits its applicability. In this study, the effects of Bifidobacterium animalis subsp. Lactis 80 (Bla80) fermentation on the physicochemical characteristics, particle size distribution, rheological properties, and volatile flavor compounds of pea milk was investigated. After fermentation by Bla80, the pH of pea milk decreased from 6.64 ± 0.01 to 5.14 ± 0.01, and the (D4,3) distribution decreased from 142.4 ± 0.47 μm to 122.7 ± 0.55 μm. In addition, Lactic acid bacteria (LAB) fermentation significantly reduced the particle size distribution of pea milk, which was conducive to improving the taste of pea milk and also indicated that Bla80 had the probiotic potential of utilizing pea milk as a fermentation substrate. According to GC-MS analysis, 64 volatile compounds were identified in fermented pea milk and included aldehydes, alcohols, esters, ketones, acids, and furans. Specifically, aldehydes in treated samples decreased by 27.36% compared to untreated samples, while esters, ketones, and alcohols increased by 11.07%, 10.96%, and 5.19%, respectively. These results demonstrated that Bla80 fermentation can significantly decrease the unpleasant beany flavor, such as aldehydes and furans, and increase fruity or floral aromas in treated pea milk. Therefore, Bla80 fermentation provides a new method to improve physicochemical properties and consumer acceptance of fermented pea milk, eliminating undesirable aromas for the application of pea lactic acid bacteria beverage.

Bacterial Cellulose Nanocrystals or Nanofibrils as Pickering stabilizers in low-oil emulsions: a comparative study.

This investigation assessed the potential of bacterial cellulose (BC) in two distinct forms, nanocrystals (BC-NC) and oxidized nanofibrils (BC-NF), as stabilizers for low oil-in-water emulsions (1 % v/v). The research explored the impact of ionic strength and BC concentration on the physico-chemical characteristics, stability, and rheological properties of those emulsions. Nanofibrils had diameters ranging from 25 to 146 nm and lengths in the micrometer range, while nanocrystals varied in length from 133 to 870 nm and in diameter from 20 to 60 nm. Both BC-NF and BC-NC exhibited high zeta potential values (> -45 mV) and contact angles of 30-31º, indicating stability. Both nanocelluloses were effectively used as stabilizers in Pickering emulsions, namely in low-oil systems, producing small emulsion droplets with sizes between 1.42 - 4.13 μm. Further results revealed that ionic strength influenced emulsion stability, with both BC-NF and BC-NC preferentially located on the surfaces of emulsion droplets in the presence of salt, as demonstrated by microscopy images. The presence of BC at the interface contributed to creating a more robust barrier against coalescence and Ostwald ripening, influencing droplet size and rheological properties. Higher BC concentrations (1 %) increased emulsion stability in the absence of salt, while at lower BC concentrations (0.5 %), salt concentration was determinant for the long-term stability of the emulsions. These findings provide valuable insights into the production of Pickering emulsions using nanocelluloses, highlighting the advantages of bio-based nanomaterials for applications in the food industry.

Physicochemical characterization, chemical composition and antioxidant activities of pyroligneous acids from cocktails of wood and agricultural residues from Ivory Coast

Physicochemical characterization, chemical composition and antioxidant activities of pyroligneous acids from cocktails of wood and agricultural residues from Ivory Coast

Physicochemical characterization, chemical composition and antioxidant activities of pyroligneous acids from cocktails of wood and agricultural residues from Ivory Coast

Physical, chemical characterization and antioxidant activities were assessed on six pyroligneous acids from four wood cocktails (WCV1, WCV2, WCV3, WCV4) and two types of agricultural residues (PA1, PA2) from Ivory Coast. Physical and chemical parameters of pyroligneous extracts were determined using a density meter, refractometer, pH meter, colorimetric titration, drying and sensory test. WCV2 alone simultaneously met all the standards set by the Japanese Pyroligneous Liquor Association, with a distinct smoky odour, a clear light-brown color, a pH of around 3, a density in the 1.010–1.020 g/mL range, and an ignition residue content of less than 0.2 %. In addition, WCV3, blackish in colour, had the highest Brix value (9) with a lower moisture content than the others (89.92 %), thus reflecting a high soluble tar content. Furthermore, all pyroligneous liquids had a high moisture content (89.92–99.08 %) and a low total acid content (0.90–2.10 %) compared with the literature. However, the results of GC-MS analysis revealed the presence of major compounds such as acetic acid, propionic acid, phenol, guaiacol and 3-methylphenol in the organic phase of pyroligneous extracts. FTIR analysis identified alkaloids, phenolic compounds and flavonoids in the aqueous phase of pyroligneous extracts. The presence of these compounds was confirmed by a phytochemical screening test. Finally, antioxidant activities with DPPH and ABTS methods showed that WCV2 had the best antioxidant properties due to its high guaiacol and syringol content. On the other hand, WCV3 showed a good antioxidant efficacy only by the DPPH method, probably due to its high flavonoid content.

Study on ferritin glycation with dextran: Physicochemical characterization and its application in the delivery of resveratrol

Ferritin exhibits promising prospects for nanoencapsulation applications, however, its susceptibility to environmental factors as a standalone carrier necessitates further consideration. In this study, the recombinant human H-chain ferritin (rHuHF) was modified with dextran (Dex) to enhance its physicochemical and functional properties. Moreover, the glycated rHuHF cavity was utilized for the encapsulation of resveratrol (Res). The results demonstrated that the glycoconjugates (Dex–rHuHF) achieved the highest grafting degree of 34.71% under the following conditions: Dex molecular weight of 40 kDa, mass ratio of rHuHF to Dex at 1:2, pH value of 7.8, relative saturation humidity of 79%, reaction temperature at 50°C, and reaction time of 30 h. Dex interacted with rHuHF and exhibited protective effects on rHuHF under extremely acidic conditions. Each Dex–rHuHF cavity encapsulated approximately 22 Res molecules with an encapsulation rate of 10.84%. The Dex–rHuHF–Res nanoparticles displayed excellent photothermal stability and sustained release properties. Furthermore, the Dex–rHuHF–Res simulated digesta showed enhanced abilities in scavenging DPPH free radicals and inhibiting α-glucosidase activity. This work investigated the impact of Dex on the physicochemical properties of rHuHF and developed a novel approach by grafting Dex onto rHuHF for encapsulating hydrophobic substances like resveratrol, which holds potential applications in water-based food and nutraceutical formulations.

Identification of Potential Lead Compounds against BCL-2 through In-silico Screening of Phytochemicals of Nigella sativa and Cuscuta reflexa for Oral Squamous Cell Carcinoma Management

Significance of the study: In silico analysis is frequently used in physicochemical characterisation, the discovery and improvement of novel compounds with affinity to a target, and the elucidation of absorption, distribution, metabolism, excretion, and toxicity features. Aim and Objective: The aim of this study is to assess the efficacy of Nigella sativa and Cuscuta reflexa in targeting Bcl2-antiapoptotic protein in Oral Squamous Cell Carcinoma through in silico analysis. Materials and Methods: The present study was designed to formulate a drug against Oral Squamous cell carcinoma against the target protein Bcl-2. Protein Database (PDB) was used to select and analyse the protein. Based on the literature search, the original molecules selected were thymoquinone, tannin pyrogallol, Cuscutin, kaempferol, nigellicine and the ligand structures were obtained ZINC15 database. Target protein structure was recognised through Protein sequence from PB (Protein Data Bank). Swiss ADME was used for assessing the properties of the molecules. Twenty new molecules were identified from zinc pharmer and docking was done for all the 20 using Swiss dock. Binding energy was assessed and compared with the original molecules.ZINC73690300 and ZINC73690304 had better binding energy than that of original molecules. Both molecules can be potential candidates for Bcl2 inhibition to prevent OSCC. Results: ZINC73690300 and ZINC73690304 had better binding energy than that of the original molecules. Both molecules can be potential candidates for Bcl-2 inhibition to prevent OSCC. Conclusion: The present study evaluated the binding energy and bioavailability of the combined extract, thus attempting to predict the target ligand binding between the compounds in OSCC before attempting in vitro studies.-

Sucrose and Glycerol Additives: A Way to Tune the Biological and Physicochemical Properties of Agarose Hydrogels?

AbstractSucrose and glycerol have gained attention as additives for hydrogels, owing to their capacity to exert considerable influence over the physicochemical, mechanical, and biological characteristics of these materials. Herein, these effects on agarose hydrogels (AHs) are explored. A series of AHs are synthesized using sucrose (30% and 300% w/v) and glycerol as additives. The storage modulus (10.0–13.7 kPa) and hydrophilicity of the hydrogels (contact angle < 50°) do not vary significantly with sucrose or glycerol addition. However, sucrose enhances the hydration capacity of the hydrogels by up to 170%, whereas glycerol reduces it. Interestingly, sucrose and glycerol individually do not have bacteriostatic effects against Staphylococcus epidermidis, but their combination significantly (p ≤ 0.001) inhibits the growth of both S. epidermidis and Pseudomonas aeruginosa by 63% and 29%, respectively, in comparison to native agarose. Cytotoxicity testing on NIH/3T3 murine fibroblasts reveals that sucrose increases cell viability up to 98%, while glycerol reduces it below 60%. Overall, these hydrogels hold promise for antibacterial biomedical applications as wound dressing materials and surface coatings for medical devices and can also be used to formulate bioinks for 3D bioprinting.

Comparison of the effect of oxygen and nitrogen plasma treatments on the surface activation of PLA/rGO composites

Cold plasma is known as a method to enhance the adsorption of proteins on the surface of biomaterials. In this experimental study, the efficacy of oxygen and nitrogen plasma treatment on the activation of Poly L-lactic acid/reduced graphene oxide composite (PLAG) was investigated. For this purpose, the chemical, physicochemical, and morphological characteristics, ability to adsorb amino acid L-tyrosine, and biological behavior of the oxygen and nitrogen plasma-treated composites (PLAG-O and PLAG-N) were studied. Following the exposure to oxygen and nitrogen plasma, (PLAG-O) composites presented more enhancement in Raman C-C and C-H bonds. The evaluation of L-tyrosine adsorption revealed the higher intensity of FTIR C-N, C-C and N-H and Raman C-H chemical bonds and also lower intensity of L-tyrosine UV absorbance in solution medium for L-tyrosine-adsorbed oxygen plasma-treated (PLAG-Ot) compared to L-tyrosine-adsorbed nitrogen plasma-treated (PLAG-Nt) composites. More apparent L-tyrosine island-shaped zones were appeared all over the surface of PLAG-Ot composites through FE-SEM experiment. Moreover, conducting detailed AFM study revealed a higher difference in surface roughness (Ra) of the PLAG-O and PLAG-Ot (140 nm) compared to the PLAG-N and PLAG-Nt composites (25 nm). From the biological point of view, the oxygen plasma-treated composites presented better HDF cell behavior in terms of viability and attachment, as well. According to the results of this study, the oxygen plasma treatment exhibits a higher potential to activate Poly L-lactic acid–reduced graphene oxide composite surface compared to the surface treatment in nitrogen plasma.

A Review on Camel Milk Composition, Techno-Functional Properties and Processing Constraints.

Camel milk plays a critical role in the diet of peoples belongs to the semi-arid and arid regions. Since prehistoric times, camel milk marketing was limited due to lacking the processing facilities in the camel-rearing areas, nomads practiced the self-consumption of raw and fermented camel milk. A better understanding of the techno-functional properties of camel milk is required for product improvement to address market and customer needs. Despite the superior nutraceutical and health promoting potential, limited camel dairy products are available compared to other bovines. It is a challenging impetus for the dairy industry to provide diversified camel dairy products to consumers with superior nutritional and functional qualities. The physicochemical behavior and characteristics of camel milk is different than the bovine milk, which poses processing and technological challenges. Traditionally camel milk is only processed into various fermented and non-fermented products; however, the production of commercially important dairy products (cheese, butter, yogurt, and milk powder) from camel milk still needs to be processed successfully. Therefore, the industrial processing and transformation of camel milk into various products, including fermented dairy products, pasteurized milk, milk powder, cheese, and other products, require the development of new technologies based on applied research. This review highlights camel milk's processing constraints and techno-functional properties while presenting the challenges associated with processing the milk into various dairy products. Future research directions to improve product quality have also been discussed.