Acid Blends Research Articles

Biocomposite Films of Amylose Reinforced with Polylactic Acid by Solvent Casting Method Using a Pickering Emulsion Approach

Binary and ternary blends of amylose (AM), polylactic acid (PLA), and glycerol were prepared using a Pickering emulsion approach. Various formulations of AM/PLA with low PLA contents ranging from 3% to 12% were mixed with AM matrix and reinforced with 25% cellulose nanofibers (CNF), and PLA-grafted cellulose nanofibers (g-CNF), the latter to enhance miscibility. Polymeric films were fabricated through solvent casting and characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Wide-Angle X-ray Scattering (WAXS), and the evaluations of physical, mechanical properties, and wettability were performed using contact angle measurements. The binary blends of AM and PLA produced films suitable for packaging, pharmaceutical, or biomedical applications with excellent water barrier properties. The ternary blends of AM/CNF/PLA and AM/g-CNF/PLA nanocomposite films demonstrated enhanced tensile strength and reduced water permeability compared to AM/PLA films. Adding g-CNF resulted in better homogeneity and increased relative crystallinity from 33% to 35% compared to unmodified CNF. The application of Pickering emulsion in creating AM-based CNF/ PLA composites resulted in a notable enhancement in tensile strength by 47%. This study presents an effective approach for producing biodegradable and reinforced PLA-based nanocomposite films, which show promise as bio-nanocomposite materials for food packaging applications.

Improving thermal stability of starches native cross-linked with citric acid as a compatibilizer for thermoplastic starch/polylactic acid blends

This study aimed to enhance compatibility and thermal stability between thermoplastic starch (TPS) and polylactic acid (PLA) by incorporating citric acid-grafted starch (CA–Starch) at different concentrations (1 and 5%) with varying degrees of substitution for starch derived from sweet potatoes and yams (DY). Blends were produced using a constant TPS/PLA weight ratio of 60:40, both with and without a compatibilizer. The blending process was carried out using a torque rheometer under two distinct conditions. The results exhibited reduced particle sizes in TPS60/PLA40/CA–Starch blends, as evidenced by SEM images displaying improved interaction and smoother surfaces. Significantly, one of the properties that experienced substantial improvement was the compatibility between TPS and PLA, as indicated by reduced phase segregation within the blends. This improvement manifested in enhanced surface morphology, smaller particle sizes, and greater homogeneity in the blends. Additionally, an enhancement in thermal properties, particularly thermal stability, was observed with higher CA content. This study underscores that the incorporation of CA–Starch not only enhances compatibility but also improves thermal stability in TPS60/PLA40 blends, offering potential for the development of biocompatible materials with superior performance.Graphical abstract

Design on thermal-mechanism coordination for binding reinforcing mesh based on shape memory polymer

The traditional rebar binding devices require complex drive and transmission mechanisms, which leads to large volume and complex structure. In this paper, a cylindrical thermoplastic shape memory polymer (SMP) fixture is proposed to verify the rebar binding method of thermal-mechanism coordination. The SMP fixture is manufactured by the injection molding technology through selecting suitable-ratio Polylactic acid and Polycaprolactone (PCL) blend materials. Besides, an additional auxiliary device is presented to overcome the incomplete recovery disadvantage existing in the thermoplastic SMP and completely achieve binding the rebar. On this base, two different binding methods are proposed to compare the mechanical performance after fixing the rebar, and the external force/thermal contributions are tested and discussed in detail. The tested results show that the binding contribution of heat could reach 70% while the binding contribution of external force could reach 30% above the transition temperature (Tg ). The maximum tensile force that the binding rebar can withstand under the thermal-mechanism coordination action could reach up to 657.7 N, which is higher than the maximum tensile force of the wire binding. In addition, the maximum friction force between rebar and notches of fixture could reach up to 94.1 N, which further verifies the feasibility of thermal-mechanism coordination for binding reinforcing mesh based on SMP fixture.

Effects of Different Essential Oil Blends and Fumaric Acid on In Vitro Fermentation, Greenhouse Gases, Nutrient Degradability, and Total and Molar Proportions of Volatile Fatty Acid Production in a Total Mixed Ration for Dairy Cattle

The present study evaluated the inclusion of fumaric acid and essential oil blends (EOBs) containing anise, cedarwood, clove, cumin, eucalyptus, garlic, ginger, lavender, lemongrass, nutmeg, oregano, and peppermint at different proportions on in vitro dry matter (DM) disappearance (DMD), fiber fraction disappearance, the efficiency of microbial production, and the total volatile fatty acids (VFAs). Ten treatments without (control treatment) or with different EOB/fumaric combinations were used in the study with eight replicates. The EOB inclusion level was 200 μL/g of feed (total mixed ration, (TMR)) while fumaric acid was administered at 3% of the TMR (DM basis). The highest DMD, in vitro true degradable DM, partitioning factor (PF24), and in vitro apparent degradable DM were recorded for the fumaric only treatment and the control. Neutral detergent fiber disappearance was reduced with the inclusion of EOB/fumaric combinations. The production of microbial mass and undegraded DM were higher (p < 0.001) for all EOBs and EOB and fumaric treatments. The inclusion of EOB and fumaric combinations reduced (p < 0.001) the total gas production, methane, and ammonia, with a higher PF24 value noted for EOB3 treatment. The inclusion of individual EOB1 containing garlic, lemongrass, cumin, lavender, and nutmeg in a ratio of 4:2:2:1:1 or combined with fumaric acid yielded the highest propionate concentration across all treatments. We concluded that EOBs decreased methane production and nutrient degradability with better results with the individual EOB1 or EOB1/fumaric combination, which showed a potential enhancement in energy production.

Stereocomplex crystallization of equimolar Poly(L-lactic acid)/Poly(D-lactic acid) blends from melt with lowered chain entanglements

Understanding polymer crystallization at the molecular level is one of the key open questions of polymer physics. Here, high molecular weight equimolar poly(L-lactic acid)/poly(D-lactic acid) (PLLA/PDLA) blends with lowered chain entanglements are prepared by the freeze-drying method. The role of chain entanglements in stereocomplex (SC) crystallization is explored. A significant increase in the crystallization kinetics of SC is observed with decreasing the entanglement density, and thus highly crystallized SC is obtained in the PLLA/PDLA blends by a process of non-isothermal crystallization. With reducing the chain entanglements of PLLA/PDLA blends, an intriguing phenomenon that SC crystallization stops at a high temperature around 200 °C and starts again at ∼160 °C on continuous cooling is observed, verifying the new concept of “poisoning by purity”. Further studies reveal that the PLLA/PDLA blends with lowered chain entanglements are more likely to form regularly folded SC lamellae, which nucleate and grow at higher temperatures. Meanwhile, the reduced chain entanglements also reduce the activation energy for chain diffusion. These two effects may be the main reason for the significantly accelerated crystallization kinetics of SC. This study provides a new idea for producing highly crystallized SC in PLLA products to improve their thermal resistance and other properties.

The In Vitro Antibacterial Activity of Phytogenic and Acid-Based Eubiotics against Major Foodborne Zoonotic Poultry Pathogens.

The aim of the study was to investigate in vitro the antibacterial activity of 8 commercial drinking water additives against major zoonotic poultry pathogens (Campylobacter spp., Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus and Listeria spp.). We tested two essential oil-based phytogenics (Phyto CSC Liquide B, AEN 350 B Liquid), two acid-based eubiotics (Salgard® liquid, Intesti-Flora), and four blends of essential oils and organic acids (ProPhorceTM SA Exclusive, Herbal acid, Rigosol-N and Eubisan 3000). The antibacterial activity was determined by estimating the minimum inhibitory concentration (MIC) using a microdilution method. The MICs of the products against Campylobacter spp. ranged from 0.071% to 0.568% v/v, in which Herbal acid, a blend rich in lactic and phosphoric acids, also containing thyme and oregano oils, exhibited the highest efficacy (MIC: 0.071% v/v) against all the tested strains. The MICs of the tested products against Escherichia coli ranged between 0.071% and 1.894% v/v. Specifically, the MIC of Rigosol-N, a blend of high concentrations of lactic and acetic acid, was 0.142% v/v for both tested strains, whereas the MICs of Intesti-Flora, a mixture rich in lactic and propionic acid, ranged from 0.284% to 0.568% v/v. The MICs of the products against Salmonella Typhimurium were between 0.095% and 1.894% v/v. Specifically, the MIC of Eubisan 3000, a blend rich in oregano oil, was 0.284% v/v. The MICs against Staphylococcus aureus were between 0.142% and 9.090% v/v. The MICs of Phyto CSC Liquide B, which is rich in trans-cinnamaldehyde, were between 3.030% and 9.090% v/v, showing the highest MIC values of all tested products. Finally, the MIC values of the tested commercial products against Listeria spp. were 0.095% to 3.030% v/v. The MICs of ProPhorceTM SA Exclusive, a highly concentrated blend of formic acid and its salts, were 0.095-0.142% v/v against Listeria spp., while the MICs of AEN 350 B Liquid were between 0.284% and 1.894% exhibiting high Listeria spp. strain variability. In conclusion, all the selected commercial products exhibited more or less antibacterial activity against pathogenic bacteria and, thus, can be promising alternatives to antibiotics for the control of zoonotic poultry pathogens and the restriction of antimicrobial-resistant bacteria.

The clinical efficacy and tolerability of a novel triple acid exfoliating blend for reducing signs of photoaging in sensitive skin.

Chemical exfoliation of the skin is a frequently utilized treatment in dermatology to improve the appearance and health of photoaged skin. Photodamaged skin is especially prone to dryness and irritation. Over-exfoliation with at-home products are partially to blame for the "epidemic" of sensitive skin affecting over half the population. Combining AHA, BHA, and PHA together creates a complementary blend that has the potential to target numerous age-related changes in the skin including the appearance of pores and smoothing skin texture, while firming skin and increasing its collagen and moisture content. The following study tested the clinical efficacy of a triple acid blend designed specifically for sensitive skin and measured improvements in signs of photodamage and hydration levels in the skin over time. Thirty females aged 35-60 with mild to moderate facial lines, wrinkles, sun damage, uneven skin tone/texture, dark spots, or pores were enrolled. Subjects were instructed to use the test article, DWB-EN, on a clean face at night 3 times weekly with 48 h between applications for 4 weeks. Statistically significant improvements were noted in all parameters of photoaging clinical assessments (wrinkles, pores, overall appearance, luminosity, visible texture, skin tone evenness, hyperpigmentation) at the end of the 4-week study period. There were no instances of skin irritation throughout the duration of this study despite half of the women having sensitive skin. Overall, this study demonstrated the clinical efficacy and tolerability of DWB-EN for treating photoaging in subjects with all skin types.

Upcycling Humins via Esterification Reactions of Hydroxyl Groups: From Functional Powders to PLA Foams and Compatibilized Blends.

The valorization of humins side streams from bio-refineries holds significant economic and sustainability potential. One plausible strategy involves using them as building blocks to create new materials. However, humins pose conceptual challenges in their natural state due to their high viscosity, processing difficulties, and temperature sensitivity. This article presents a synthetic strategy for modifying humins properties to make them thermally stable and processable. Employing a sequence of esterification reactions and varying the reagent steric length, we showcase the selective transformation of humins into thermally-stable fine powders and low-viscosity liquids. We extend this approach by reacting humins with polyesters such as polylactic acids and polycaprolactone. In particular, we detail a one-pot single-step synthesis of micro-phase separated compatibilized blends of polylactic acid and humins capped with the polylactic acid arms. Processed via solution-casting, the obtained materials behave as high-strength thermoplastic elastomers having uniform foam morphologies and material characteristics superior to the pure polylactic acid. By varying the content of D-enantiomers, we demonstrate an additional possibility of manipulating the cellular structures of the foams. Finally, we provide a solution to product circularity by reporting a dissolution recycling method.

A novel hepatocyte ketone production assay to help the selection of nutrients for the ketogenic diet treatment of epilepsy

The classic ketogenic diet is an effective treatment option for drug-resistant epilepsy, but its high fat content challenges patient compliance. Optimizing liver ketone production guided by a method comparing substrates for their ketogenic potential may help to reduce the fat content of the diet without loss in ketosis induction. Here, we present a liver cell assay measuring the β-hydroxybutyrate (βHB) yield from fatty acid substrates. Even chain albumin-conjugated fatty acids comprising between 4 and 18 carbon atoms showed a sigmoidal concentration-βHB response curve (CRC) whereas acetate and omega-3 PUFAs produced no CRC. While CRCs were not distinguished by their half-maximal effective concentration (EC50), they differed by maximum response, which related inversely to the carbon chain length and was highest for butyrate. The assay also suitably assessed the βHB yield from fatty acid blends detecting shifts in maximum response from exchanging medium chain fatty acids for long chain fatty acids. The assay further detected a dual role for butyrate and hexanoic acid as ketogenic substrate at high concentration and ketogenic enhancer at low concentration, augmenting the βHB yield from oleic acid and a fatty acid blend. The assay also found propionate to inhibit ketogenesis from oleic acid and a fatty acid blend at low physiological concentration. Although the in vitro assay shows promise as a tool to optimize the ketogenic yield of a fat blend, its predictive value requires human validation.

Chicken intestinal organoids: a novel method to measure the mode of action of feed additives.

There is a rapidly growing interest in how the avian intestine is affected by dietary components and feed additives. The paucity of physiologically relevant models has limited research in this field of poultry gut health and led to an over-reliance on the use of live birds for experiments. The development of complex 3D intestinal organoids or "mini-guts" has created ample opportunities for poultry research in this field. A major advantage of the floating chicken intestinal organoids is the combination of a complex cell system with an easily accessible apical-out orientation grown in a simple culture medium without an extracellular matrix. The objective was to investigate the impact of a commercial proprietary blend of organic acids and essential oils (OA+EO) on the innate immune responses and kinome of chicken intestinal organoids in a Salmonella challenge model. To mimic the in vivo prolonged exposure of the intestine to the product, the intestinal organoids were treated for 2 days with 0.5 or 0.25 mg/mL OA+EO and either uninfected or infected with Salmonella and bacterial load in the organoids was quantified at 3 hours post infection. The bacteria were also treated with OA+EO for 1 day prior to challenge of the organoids to mimic intestinal exposure. The treatment of the organoids with OA+EO resulted in a significant decrease in the bacterial load compared to untreated infected organoids. The expression of 88 innate immune genes was investigated using a high throughput qPCR array, measuring the expression of 88 innate immune genes. Salmonella invasion of the untreated intestinal organoids resulted in a significant increase in the expression of inflammatory cytokine and chemokines as well as genes involved in intracellular signaling. In contrast, when the organoids were treated with OA+EO and challenged with Salmonella, the inflammatory responses were significantly downregulated. The kinome array data suggested decreased phosphorylation elicited by the OA+EO with Salmonella in agreement with the gene expression data sets. This study demonstrates that the in vitro chicken intestinal organoids are a new tool to measure the effect of the feed additives in a bacterial challenge model by measuring innate immune and protein kinases responses.

Distinguishing Turkish pine honey from multi-floral honey through MALDI-MS-based N-glycomics and machine learning

Honey, a multifaceted blend of sugars, amino acids, vitamins, proteins, and minerals, exhibits compositional variability dependent upon the floral source. While previous studies have attempted to categorize honey, the use of glycomic profiles for honey classification remains an unexplored avenue. This investigation seeks to establish a methodology for distinguishing honey types, specifically multi-floral and pine honey, employing mass spectrometry-based glycomic analysis in tandem with machine learning. In this search, seven samples of pine honey and eight samples of multi-floral honey were obtained from diverse regions of Turkey. Subsequently, the proteins within these honey samples were extracted, and glycans were enzymatically released. The released glycans were labeled with 2-aminobenzoic acid (2-AA) and subjected to analysis via matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The glycan profiles of pine and multi-floral honey were determined through these analytical procedures, revealing a total of 76 distinct N-glycan structures. Among these, 13 N-glycan profiles consistently established at high levels across experimental replicates and were incorporated in subsequent analyses. Following the quantification of individual glycan abundances, statistically significant differences in glycan profiles were determined. Notably, N-glycans Hex5HexNAc2, Hex4HexNAc3, and Hex5HexNAc3 displayed considerable differences. Using the 13 N-glycan profiles, an accuracy rate of 93.5% was obtained from machine learning analysis, which increased to 100% when incorporating the identified significantly changed glycans. The most productive models were identified as “subspace and fine k-nearest neighbors (KNN).” The findings underscore the potential of mass spectrometry-based glycomics in conjunction with machine learning as a robust tool for precise honey type classification and its prospective utility in quality control and honey product authentication.

Super-tough polylactic acid blends via tunable dynamic vulcanization of polyurethanes with ultrahigh bio-based content

Polylactic acid (PLA), a biodegradable plastic derived from renewable resources, is commercially available but has been limited in application owing to its inherent brittleness. To address this, researchers explored a reactive blending strategy using polyurethane (PU) to enhance PLA toughness. This method is straightforward and effective, yet most PUs are derived from petroleum or containing low bio-based content. Herein, we developed a bio-based PU (BPU) with double bonds for dynamic vulcanization to toughen PLA, using 1,3-polypropanediol (PO3G) and 1,5-pentane diisocyanate (PDI) with an ultrahigh bio-based content of 93.8 %. The toughness and tensile strength of the PLA/BPU blends were adjustable by modifying the BPU content. In particular, the toughness of the blends could reach 68.69 kJ/m2 by varying the amount of BPU. In addition, the BPU20–0.1 sample demonstrated an optimal balance of stiffness and toughness, exhibiting a tensile strength of 47.8 MPa and a notched impact strength of 54.86 kJ/m2. This research broadens the scope for toughening PLA using BPUs, thereby diminishing the dependency on petrochemical resources.

Attractant and repellent properties of Senna didymobotrya plant extracts to Amblyomma variegatum and Rhipicephalus appendiculatus

The growing challenge of acaricide resistance and geographical range expansion of invasive tick species demands other interventions, like plant-based alternatives, for sustainable tick control. Leaves, flowers, seedpods, and twig branch extracts of Senna didymobotrya were analyzed using coupled gas chromatography mass spectrometry (GC-MS). Response of adult Amblyomma variegatum and Rhipicephalus appendiculatus to extracts was evaluated. The most attractive plant extract was fractionated and ticks’ responses to its fractions assessed. Potential tick attractants in the attractive plant part extract and its fractions were identified by GC-MS analysis. Non- significant qualitative and quantitative differences were observed in the plant parts’ extract composition (R = 0.6178). Flower extracts attracted both species, with a 0.1-fold higher attraction in A. variegatum compared to the standard attraction aggregation attachment pheromone (AAAP). Leaf and seedpod extracts repelled ticks at various concentrations. Bioassays after fractionating flower extracts identified hexane and ethyl acetate fractions as most attractive to A. variegatum (P < 0.001) and R. appendiculatus (P < 0.001), respectively. Chemical analysis of the most attractive extracts and fractions identified compounds, including documented acarine attractants, squalene and linoleic acid. A squalene and linoleic acid blend (1:1) at 1 mg/mL significantly attracted adult A. variegatum (P < 0.01) and R. appendiculatus (P < 0.001). The results of this study broaden comprehension of how ticks respond to plants in nature, and showcase the promising potential for integrating these insights into effective tick management programs.

Exploring the potentialities of a biodegradable polymeric film in sample preparation: An optimized “white” protocol to extract and quantify emerging contaminants in water

BackgroundThe introduction of white analytical chemistry encourages the development of methods characterized by a balance among greenness, productivity/feasibility and analytical performances. In the environmental analysis of emerging contaminants (ECs), for which high sensitivity and specificity are mandatory, the use of green and sustainable sample preparation needs to be coupled to a reliable analytical determination. Herein, an extraction method based on the use of a biodegradable polymeric film (Mater-Bi) and coupled to LC-MS/MS analysis was developed for the sensitive determination of ECs in wastewater. ResultsThe interaction among a range of ECs and the Mater-Bi film (a commercially available patented blend of polybutylene-terephthalate, starch and fatty acids) was investigated by two sequential experimental designs, to simultaneously study several factors and optimize extraction efficiency. The final method, resembling a fabric phase sorptive extraction, involved pH and ionic strength modification of the sample, 1h extraction and desorption in ethanol. Satisfactory recoveries from real wastewater were obtained for sixteen analytes (56–116 %), as well as excellent precision (inter-day relative standard deviations below 10 % for most compounds). Matrix effect was in the range 88–116 % at the lower pre-concentration factor, but also acceptable in most cases at the higher pre-concentration factor. LODs in matrix, from 0.004 to 0.159 μg L−1, were lower than or comparable to those from recent studies employing green extraction procedures. The method demonstrated its applicability to samples from wastewater treatment plants, allowing quantification of pharmaceuticals and UV filters at the μg L−1 and ng L−1 levels, respectively. SignificanceFor the first time, the synthetic biopolymer Mater-Bi, so far unexplored for the use in analytical chemistry, was exploited for a green, simple and extremely cheap extraction protocol. The optimized method is suitable for several ECs, guaranteeing very good accuracy, precision and specificity, also thanks to the LC-MS/MS analysis. The evaluation by green and white analytical chemistry metrics highlighted its superiority to conventional extraction methods.

Effect of poly(lactic acid) molecular weight and composition on the morphology and crystallization behavior of polyhydroxybutyrate/poly(lactic acid) blends

AbstractThis study investigates the effects of molecular weight and crystallinity of polylactic acid (PLA) on the morphology and crystallization behavior of polyhydroxybutyrate (PHB)/PLA blends. Utilizing a solution casting method, we discovered that the molecular characteristics of PLA significantly influence the thermal and structural properties of the blends. The lower molecular weight and amorphous PLA notably broadened the temperature range for PHB's banded spherulite formation, indicating enhanced miscibility. In contrast, semicrystalline PLA variants produced smaller spherulites within large PHB matrices. The high molecular weight PLA had an unusual, relatively low melting point which led to a competition between the molecular weight effect and the supercooling effect regarding the isothermal crystallization kinetics. The blend morphology was observed in thin films in which the usual crystal formation of PHB was severely hindered in the presence of crystalline PLA but could form thin lamellae when the PLA was amorphous. At ultra‐thin thickness, where crystallization is impossible, the amorphous co‐continuous structure of the blends was revealed by melting the film. Our research contributes to the development of advanced biodegradable materials for environmental sustainability, emphasizing the intricate interplay between polymer blend components that can be tuned for specific applications.Highlights The study explores the blend morphology and crystallization of PLA/PHB. The temperature range for PHB's spherulite formation broadens with PLA. PLA's partial miscibility with PHB shifted Tg and caused delayed Tm of PHB. Usual PHB crystal formation is hindered with crystalline PLA. Thin PHB lamellae formed within amorphous PLA and observed via AFM.

Research note: A scald water surfactant combined with an organic acid carcass dip reduces microbial contaminants on broiler carcasses during processing

Organic acids are applied to poultry carcasses during processing to reduce foodborne pathogens and spoilage microorganisms. Scald water surfactant agents employed to improve feather removal may enhance the efficacy of organic acids during processing. This study investigated the effects of concurrent application of a scald water surfactant and organic acid dip on microbial contamination of carcasses processed in a small-scale production model. Broilers were reared in litter floor pens to 47 d of age and slaughtered using standard practices. Carcasses were scalded in either control or surfactant scald water initially and dipped in either a 2% organic acid blend or water after feather removal to complete a 2 × 2 factorial arrangement with n = 15 carcasses per treatment group. The commercially available scald water additive was a slightly alkaline surfactant solution labelled as a feather removal aid. The organic acid dip consisting of lactic and citric acid was maintained at pH of 2.5. Approximately 10 g of neck skin was collected 1-min postdipping and placed in buffered peptone water with an added neutralizing agent, sodium thiosulfate. Serial dilutions were performed to determine general coliform (GC), E. coli (EC), and aerobic plate (APC) counts as CFU per gram of skin sample. A significant 0.61, 0.76, and 1.6 log reduction of GC, EC, and APC, respectively, was attributed to use of the organic acid carcass dip (P ≤ 0.01). There were no significant differences in carcass microbial reduction due to surfactant scald water alone. A 0.69, 0.73 (P ≤ 0.05), and 1.96 log reduction of GC, EC, and APC, respectively, was observed in surfactant-scalded, acid-dipped carcasses compared to water-scalded, water-dipped control groups. These data demonstrated that a surfactant scald water additive and an organic acid carcass dip can have beneficial effects of microbial reduction when employed simultaneously during broiler processing.

Tailored synthesis of pH-responsive biodegradable microcapsules incorporating gelatin, alginate, and hyaluronic acid for effective-controlled release

In response to escalating environmental concerns and the urgent need for sustainable drug delivery systems, this study introduces biodegradable pH-responsive microcapsules synthesized from a blend of gelatin, alginate, and hyaluronic acid. Employing the coacervation process, capsules were created with a spherical shape, multicore structure, and small sizes ranging from 10 to 20 μm, which exhibit outstanding vitamin E encapsulation efficiency. With substantial incorporation of hyaluronic acid, a pH-responsive component, the resulting microcapsules displayed noteworthy swelling behavior, facilitating proficient core ingredient release at pH 5.5 and 7.4. Notably, these capsules can effectively deliver active substances to the dermal layer under specific skin conditions, revealing promising applications in topical medications and cosmetics. Furthermore, the readily biodegradable nature of the designed capsules was demonstrated through Biochemical Oxygen Demand (BOD) testing, with over 80 % of microcapsules being degraded by microorganisms after one week of incubation. This research contributes to the development of responsive microcapsules and aligns with broader environmental initiatives, offering a promising pathway to mitigate the impact of microplastics while advancing various applications.

Effects of porcine somatotropin administration on the responses to dietary lysine and a near-ideal blend of amino acids on the amino acid composition of whole-body protein and amino acid accretion rate in growing pigs.

An experiment was conducted to assess the effects of porcine somatotropin (pST) on the responses to a near-ideal blend of AA on the AA composition of empty, whole-empty body (WEB) protein and WEB essential AA accretion rate in pigs from 22 to 60kg BW. Forty Hampshire × Yorkshire gilts were individually penned and assigned to a 4 × 2 factorial arrangement of treatments consisting of four diets with and without pST injection. A fortified corn-soybean meal basal diet was formulated to contain 1.50% total Lys with Thr, Met, and Trp added to obtain a near-ideal blend of these AA relative to Lys. In three additional diets, Lys was reduced to 1.25%, 1.00%, and 0.75% by diluting the basal diet with cornstarch, cellulose, and sand such that the diets also contained the same ratios of AA. Pigs that received pST were administered a daily i.m. injection of 2mg of pST. At 60kg BW, the WEB (carcass, head, viscera, blood, nails, and hair) was ground and analyzed for proximate and AA composition. Administration of pST increased (P < 0.001) accretion rates of WEB protein and essential AA. Increasing dietary essential AA increased (quadratic, P < 0.03) accretion rate of WEB protein, His, Leu, Trp, and Val in pST-treated pigs, but not in untreated pigs. Lysine composition in the accreted WEB protein was not affected (P > 0.05) by dietary Lys. The efficiency of Lys utilization for WEB Lys accretion was linearly affected (P < 0.01) by dietary Lys. These results indicated that the dietary Lys needed to achieve maximum WEB Lys accretion is markedly increased by pST administration.

3D hydrogel microfibers promote the differentiation of encapsulated neural stem cells and facilitate neuron protection and axon regrowth after complete transactional spinal cord injury

Spinal cord injury (SCI) can cause permanent impairment to motor or sensory functions. Pre-cultured neural stem cell (NSC) hydrogel scaffolds have emerged as a promising approach to treat SCI by promoting anti-inflammatory effects, axon regrowth, and motor function restoration. Here, in this study, we performed a coaxial extrusion process to fabricate a core-shell hydrogel microfiber with high NSC density in the core portion. Oxidized hyaluronic acid, carboxymethyl chitosan, and matrigel blend were used as a matrix for NSC growth and to facilitate the fabrication process. During the in vitro differentiation culture, it was found that NSC microfibers could differentiate into neurons and astrocytes with higher efficiency compared to NSC cultured in petri dishes. Furthermore, during in vivo transplantation, NSC microfibers were coated with polylactic acid nanosheets by electrospinning for reinforcement. The coated NSC nanofibers exhibited higher anti-inflammatory effect and lesion cavity filling rate compared with the control group. Meanwhile, more neuron- and oligodendrocyte-like cells were visualized at the lesion epicenter. Finally, axon regrowth across the whole lesion site was observed, demonstrating that the microfiber could guide renascent axon regrowth. Experiment results indicate that the NSC microfiber is a promising bioactive treatment for complete SCI treatment with superior outcomes.

Continuous fabrication of braided composite nanofibrous surgical yarns using advanced AC electrospinning and braiding technology

Composite nanofibrous yarns (CNY), featuring a submicron electrospun sheath coated on a micro-scale core yarn have gained attention within the academic and industrial communities due to their unique structure. When braided, these CNYs hold great promise as next-generation surgical yarns. However, large-scale production of CNYs using conventional electrospinning techniques remains technologically challenging, and maintaining the integrity of the fibrous sheath during braiding presents further difficulties. Here, we propose a novel approach for continuously fabricating functional braided CNYs using collectorless alternating current (AC) electrospinning and braiding technology. Our approach utilized polycaprolactone-polylactic acid (PCL-PLA) blends and PCL-PLA with chlorhexidine (CHX) or triclosan (TRC) electrospun fibers for the sheath layer, while PLA micro-yarns acted as the core layer. Morphological analyses confirmed the successful fabrication of braided CNYs. Additionally, infrared spectroscopy validated the presence of CHX or TRC in the resulting yarns. The resulting braided CNYs exhibited excellent breaking force (29 N) and thermal stability (270 °C). Cytotoxicity and antibacterial assessments demonstrated that CHX-loaded braided CNYs could serve as biocompatible antibacterial surgical sutures. The proposed method offers a versatile approach for producing various functional braided CNYs applicable in tissue engineering scaffolds, filters, wearable electronics, and sensors.