Preparation and FTIR, Raman and SEM characterizations of konjac glucomannan-KCl electrogels

Synergistic kappa-carrageenan/konjac-glucomannan hydrogels for the tunable and controlled release of biomimetic nanoparticles

Biomimetic nanoparticles (BNPs), which integrate biologically active materials such as cell membrane proteins, represent an emerging class of nanoparticles with therapeutic potential. However, the controlled release of these nanoparticles from hydrogels remains challenging due to their relatively large size compared to the hydrogel mesh size, which hinders diffusion. This research aimed to fabricate a dissolvable hydrogel platform incorporating novel BNPs for controlled release and to evaluate its therapeutic effects. Specifically, we developed a procedure for the fabrication of synergetic hydrogel using two soluble polysaccharides, namely konjac glucomannan (KGM) and kappa-carrageenan (KCAR), at low temperatures that preserve the BNPs' biological functionality. The physical, mechanical, and rheological properties of these hydrogels, as well as the controlled release of BNPs, were characterized. The results demonstrate the self-healing and shear-thinning properties of the hydrogels. Using potassium ions as a physical cross-linker improved the hydrogel's mechanical properties and allowed the tuning of the BNPs' release rate. Additionally, in vitro tests in an inflammation model showed that the BNPs containing hydrogel reduced tumor necrosis factor-alpha (TNF α) cytokine levels without significantly affecting cell viability. This novel hydrogel platform offers a promising approach for the tunable controlled release of BNPs, with potential applications for inflammation and other therapeutic models.

Characterization of Sucrose-Impregnated Crystalline Glucose/Mannose Films as Moisturizing Wound Dressings and Their Significant Healing Effect on Deep Wounds in a Rat Model

Crystalline glucose/mannose film (G/M) demonstrated excellent water absorptivity and a high vapor transmission rate. The film had excellent wound healing performance. However, the crystallinity of the G/M tended to be disrupted when swollen, leading to a loss of mechanical strength. Herein, novel sucrose-impregnated G/M dressings were prepared to overcome this shortcoming. Sucrose has been claimed to promote angiogenesis and re-epithelization. This study evaluated the additive effect of sucrose on G/M films at different concentrations (G/M-0% (G/M-H2O), G/M-30% sucrose, and G/M-70% sucrose) regarding their material properties and wound healing performance. Both sucrose-impregnated G/M films demonstrated a lower degree of decrease in crystallinity than the control G/M-H2O film. This resulted in a significant improvement in stress and elongation at break for G/M-70% sucrose. In the in vivo study, G/M-70% sucrose was most effective in deep wound healing compared to other sucrose concentrations, with complete wound closure at 1 week. This was evidenced by the early regeneration of the mature epidermal layer, which promoted angiogenesis and the deposition of thicker and oriented collagen fibers. This study demonstrated the additive effect of sucrose on G/M, suggesting that the novel sucrose-impregnated G/M dressing is a promising candidate for deep wound healing.

Chitosan and inulin synergized with Lactiplantibacillus plantarum LPP95 to improve the quality characteristics of low-salt pickled tuber mustard

Low-salt pickled vegetables are in line with a healthier diet, yet ensuring consistent quality of such products is challenging. In this study, low-salt tuber mustard pickles fermented with Lactiplantibacillus plantarum LPP95 in the presence of chitosan and inulin were analyzed over a 30-day period, and quality changes were evaluated. Total acid productions along with high bacterial counts (106 CFU/mL) were observed in the initial 20 days during indoor storage temperature, in which the reduced fiber aperture was found significantly lead to an increase in crispness (16.94 ± 1.87 N) and the maintenance of a low nitrate content (1.23 ± 0.01 mg/kg). Moreover, the combined pickling treatment resulted in higher malic acid content, lower tartaric acid content, and a decrease in the content of bitter amino acids (e.g., isoleucine and leucine), thus leading to an increase in the proportion of sweet amino acids. Additionally, combined pickling led to the production of unique volatile flavor compounds, especially the distinct spicy flavor compounds isothiocyanates. Moreover, the combined pickling treatment resulted in an increase in the abundance of Lactiplantibacillus and promoted microbial diversity within the fermentation system. Thus, the synergistic effect among chitosan, inulin, and L. plantarum LPP95 significantly enhanced the quality of pickles. The study offers a promising strategy to standardize the quality of low-salt fermented vegetables.

IR-EcoSpectra: Exploring sustainable ex situ and in situ FTIR applications for green chemical and pharmaceutical analysis

In various industries, particularly in the chemical and pharmaceutical fields, Fourier transform infrared spectroscopy (FTIR) spectroscopy provides a unique capacity to detect and characterise complex chemicals while minimising environmental damage by minimal waste generation and reducing the need for extensive sample preparation or use of harmful reagents. This review showcases the versatility of ex situ and in situ FTIR applications for substance identification, analysis, and dynamic monitoring. Ex situ FTIR spectroscopy's accuracy in identifying impurities, monitoring crystallisation processes, and regulating medication release patterns improves product quality, safety, and efficacy. Furthermore, its quantification capabilities enable more effective drug development, dosage procedures, and quality control practices, all of which are consistent with green analytical principles. On the other hand, in situ FTIR spectroscopy appears to be a novel tool for the real-time investigation of molecular changes during reactions and processes, allowing for the monitoring of drug release kinetics, crystallisation dynamics, and surface contacts, as well as providing vital insights into material behaviour. The combination of ex situ FTIR precision and in situ FTIR dynamic capabilities gives a comprehensive analytical framework for developing green practices, quality control, and innovation in the chemical and pharmaceutical industries. This review presents the wide range of applications of ex situ and in situ FTIR spectroscopy in chemical, pharmaceutical and medical fields as an analytical green chemistry tool. However, further study is required to fully realise FTIR's potential and develop new applications that improve sustainability in these areas.

Fabrication of gastro-floating sustained-release etoricoxib and famotidine tablets: design, optimization, in-vitro, and in-vivo evaluation

In this study, a new gastro-floating sustained-release tablet (GFT) with a combination of Etoricoxib (ET) and Famotidine (FM) was successfully developed. GFTs were prepared by using a combination of hydrophilic swellable natural/semi-synthetic polymers as a controlled-release layer. Through a 24 full factorial statistical experimental design, the effects of formulation factors on the release of GFTs were conducted. The ideal floating tablet (FT) comprised konjac-gum (150 mg), guar-gum (26.57 mg), xanthan-gum (54.17 mg), and HPMC-K15-M (69.25 mg). The ideal FT exhibited a high swelling index (SI) (297.7%) and rapid FLT (around 50 s) in 0.1 N HCl as well as controlled release of ET (22.43% in 1 h and 77.47% in 8 h) and FM (24.89% in 1 h and 93.82% in 8 h) with the absence of any drug-excipient interactions. The AUC0∼72 (ng h/mL) of ET and FM in the GFTs were approximately double-fold of the market, respectively. The relative bioavailability was (207.48 ± 12.02% and 208.51 ± 13.11%) compared with commercial tablets. The X-ray imaging showed a promising buoyancy ability for approximately 8 h. These findings revealed the successful preparation of the sustained-release floating tablet with improved dual drug delivery.

Merging konjac glucomannan with other copolymeric hydrogels as a cutting-edge liquid raft system for dual delivery of etoricoxib and famotidine

This study aimed to formulate and evaluate a floating raft system for the co-delivery of etoricoxib (ETO) and famotidine (FAM) using a combination of glucomannan with natural/semi-synthetic polysaccharides. Formulation variables affect gelation lag time (GLT), floating lag time (FLT), and release percentage of drugs after 1-8 h, Stability, and viscosity parameters were evaluated. In vivo X-ray studies, followed by the pharmacokinetic study, were performed on human volunteers. Formulations exhibited pseudoplastic behavior for ease of swallowing. The optimum raft system (ORS) comprised 1% Na alginate, 0.1% Low Methoxyl (LM) pectin, 0.8% Konjac glucomannan (KGL), 1% Precirol, and 1% CaCO3. ORS exhibited rapid GLT and FLT (around 42 and 8 sec respectively) in 0.1 N HCl as well as controlled release of ETO (15% in 1 h and 82% in 8 h) and FAM (29% in 1 h and 85% in 8 h). Formulation stability with the absence of any drug-excipient interactions was observed. The X-ray imaging showed a promising buoyancy ability for approximately 8 h. Compared with marketed products, ORS showed superior relative bioavailability for both drugs. These findings revealed the successful preparation of a promising raft system with improved dual drug delivery.

Review of Konjac Glucomannan Structure, Properties, Gelation Mechanism, and Application in Medical Biology

Konjac glucomannan (KGM) is a naturally occurring macromolecular polysaccharide that exhibits remarkable film-forming and gel-forming properties, and a high degree of biocompatibility and biodegradability. The helical structure of KGM is maintained by the acetyl group, which plays a crucial role in preserving its structural integrity. Various degradation methods, including the topological structure, can enhance the stability of KGM and improve its biological activity. Recent research has focused on modifying KGM to enhance its properties, utilizing multi-scale simulation, mechanical experiments, and biosensor research. This review presents a comprehensive overview of the structure and properties of KGM, recent advancements in non-alkali thermally irreversible gel research, and its applications in biomedical materials and related areas of research. Additionally, this review outlines prospects for future KGM research, providing valuable research ideas for follow-up experiments.

Investigation on the influence of AC electric filed and KCl on the structure and gel properties of Konjac glucomannan

The influence of alternating current (AC) electric field and KCl on the structure and gel properties of Konjac Glucomannan (KGM) were studied in this work by high-performance gel permeation chromatography (HPGPC), acid-base titration, solid-state nuclear magnetic resonance (NMR), X-ray diffraction (XRD), simultaneous differential scanning calorimetry/thermo gravimetric analyzer (DSC/TGA) and a rheometer. HPGPC showed KGM was degraded by AC electric field and Acid-base titration showed that under the action of AC electric field and KCl KGM removed part of acetyl groups, which were consistent with the analysis of NMR. XRD and temperature sweep measurements respectively showed that the electrotreatment time and KCl concentration had important effects on the gel formation and its three-dimensional network. Simultaneous DSC/TGA and temperature sweep measurements both demonstrated the gel had good thermal stability.

Air packaging is obviously beneficial to the heterogeneous hygrothermal degradation of konjac glucomannan

Heterogeneous hygrothermal degradation (HHTD) is a cost-effective and environmentally friendly method for the successful preparation of partially depolymerized konjac glucomannan (DKGM). This study investigated the degradation of konjac glucomannan (KGM) in two packaging methods and detected that compared with natural KGM, the M_w of vacuum-packaged DKGM with 20 % moisture content treated at 130 °C for 40 min was reduced by 23.34 %, while that of air-packaged DKGM was decreased by 63.14 %, the vacuum-packaged DKGM with only 0.5 % H₂O₂ added was dropped by 69.36 %. It was verified that oxygen in air-packaging plays a crucial role in HHTD. Furthermore, the effects of moisture content, treatment temperature and time on the M_w and apparent viscosity of air-packaged DKGM were explored. The properties and structure of DKGM were characterized by rheometer, TGA, XRD, FT-IR and SEM. Results established that treatment temperature had a stronger promoting effect on HHTD. The rheological properties of DKGM samples changed markedly, and the thermal decomposition temperature and crystallinity were increased, with its infrared absorption peaks very close. This research is expected to provide theoretical bases and reference ideas for efficient HHTD method of KGM in actual production.

Development of β-Cyclodextrin/Konjac-Based Emulsion Gel for a Pork Backfat Substitute in Emulsion-Type Sausage

Emulsion gel has been used to replace animal fats in meat products. Konjac is a widely used gelling agent; however, its low emulsion stability limits its use in meat products. This study aimed to examine the quality characteristics of β-cyclodextrin (CD)-supplemented konjac-based emulsion gel (KEG) (CD-KEG) and its application as a fat substitute in emulsion-type sausages. The supplementation of CD increased hydrogen bonds and hydrophobic interactions with konjac and oil in the gels, respectively. Additionally, CD increased the structural complexity and strength of KEG. Since adding more than 6% of CD to KEG did not increase the gel strength, 6% CD-added KEG was adopted to substitute for pork backfat in manufacturing low-fat emulsion-type sausages. The following formulations of the sausages were prepared: pork backfat 20% (PF20); pork backfat 10% + KEG 10% (KEG10); KEG 20% (KEG20); pork backfat 10% + CD-KEG 10% (CD-KEG10); CD-KEG 20% (CD-KEG20); and pork backfat 5% (PF5). The CD-KEG20 formulation exhibited higher viscosity and viscoelasticity than KEG20, which suggested that CD improves the rheological properties and the thermal stability of meat batter. Additionally, CD-KEG20 showed similar emulsion stability, cooking yield and texture parameters compared with PF20. Therefore, 6% CD-added KEG is a suitable fat substitute for preparing low-fat emulsion-type sausages.

Synthesis of biocompatible Konjac glucomannan stabilized silver nanoparticles, with Asystasia gangetica phenolic extract for colorimetric detection of mercury (II) ion

Herein, the synthesis of a biocompatible silver nanoparticles (AgNPs), for colorimetric detection of toxic mercury (II) ion (Hg²⁺), is reported. Phenolic-rich fraction of Asystasia gangetica leaf was extracted and used as a reductant of silver salt, all within the hydrophilic konjac glucomannan (KgM) solution as stabilizer, at room temperature (RT). The bioactive components of Asystasia gangetica phenolic extract (AGPE), as elucidated with a (UHPLC-MS-QTOF-MS), revealed plethora of phenolic compounds, which can facilitate the reduction of silver salt at ambient conditions. Sparkling yellow colloidal solution of KgM-AgNPs was realized within 1 h, at RT, having a UV–vis maximum at 420 nm. KgM-AgNPs was characterized using UV–vis, Raman and (FTIR), TEM, SEM, EDS, XRD, TGA/DTG. TEM and FESEM images showed that KgM-AgNPs were spherical, with particle size distribution around 10–15 nm from TEM. The KgM-AgNPs biocompatibility was investigated on mouse L929 fibrobroblast and rat erythrocytes, without any harmful damages on the tested cells. In aqueous environment, KgM-AgNPs demonstrated good detection capacity toward Hg²⁺, in a Hg²⁺ concentration dependent fashion, within 3 min. Absorbance ratios (A₃₆₀/A₄₀₈) was linear with Hg²⁺ concentrations from 0.010–10.0 to 10.0–60.0 µM, with an estimated (LOD) of 3.25 nM. The probe was applied in lake water sample, with satisfactory accuracy.

The Efficiency of Lemon Essential Oil-Based Nanoemulsions on the Inhibition of Phomopsis sp. and Reduction of Postharvest Decay of Kiwifruit

Essential oils (EOs) have excellent antibacterial activity and are generally recognized as safe (GRAS) for use in food preservatives. However, the application of EOs is limited because of their strong volatility and easily oxidized. Encapsulation of EOs into nanoemulsions could effectively prevent oxidative deterioration. In this study, lemon essential oil-based nanoemulsion (LEO/NE) was prepared by high-pressure homogenization. FT-IR and encapsulation efficiency analysis indicated that LEO was effectively encapsulated in the nanoemulsion. The results of zeta potential changes after 35 d storage indicated that LEO/NE exhibits good stability at room temperature. The effect of LEO/NE on the main soft rot pathogens of kiwifruit Phomopsis sp. was investigated, and the results showed that LEO/NE significantly inhibited spore germination and mycelia growth of Phomopsis sp. by promoting ROS accumulation, intracellular antioxidant enzyme activities, and cell apoptosis. The preservation experiment was carried out by inoculating Phomopsis sp. spores into fresh kiwifruit, and the LEO/NE effectively inhibited soft rot development in kiwifruit in a LEO dose dependent manner. LEO/NE with 1% LEO loading amount has a good effect on preventing postharvest decay of kiwifruit caused by Phomopsis sp.

Konjac glucomannan films with quasi-pasteurization function for tangerines preservation

This study presents functional KCNGO films obtained by incorporating graphite carbon nitride (g-C₃N₄) and graphene oxide (GO) into the konjac glucomannan (KGM) matrix. The concept of quasi-pasteurization proposed in current work refers to the shorter time needed and lower sterilization temperature used than that of the conventional pasteurization. The films had a compact microstructure formed by the hydrogen bond interactions, as revealed by morphology characterization, FTIR and rheological analysis. It also had excellent hydrophobicity, thermal stability, mechanical properties and water vapor barrier ability. Notably, this film exhibited potent bactericidal activity against foodborne pathogens based on functions of fast heating and instantaneous low temperature bactericidal (4 min, 55 ± 1 °C). The quasi-pasteurization efficacy and mechanism of films were explored. Moreover, this film was safe and can keep the "fresh-like" characteristics of the tangerines for 24 days. Therefore, a quasi-pasteurization strategy is provided in food preservation field.