Preparation, Physicochemical Characterization, and Antioxidant Activity of Naringin–Silk Fibroin–Alginate Microspheres and Application in Yogurt

Preparation of pH-enzyme dual-responsive gel microspheres and their treatment of ulcerative colitis

Mesalazine (MSZ), a first-line treatment for ulcerative colitis (UC), was formulated into acid-resistant, colon-targeted gel microspheres to reduce upper gastrointestinal tract (GIT) exposure and extend drug retention in the colon. In this study, we used MSZ/hydroxypropyl-β-cyclodextrin (MSZ/HP-β-CD) as the model drug, dopamine-modified sodium alginate (DA-SA) and konjac glucomannan (KGM) as the carrier matrix, and chitosan (CS) as the coating material. The colon-targeted gel microspheres (MSZ/HP-β-CD/DA-SA/KGM/CS) were prepared using the drop method. These microspheres had a drug loading capacity of 7.9 ± 0.01 % and an encapsulation efficiency of 72.5 ± 0.03 %. The drug primarily released in the colon environment, showing pH and β-mannanase sensitivity. The dried microspheres measured approximately 0.6 mm, suitable for oral administration. In the rat UC model, after oral administration of gel microspheres, the colon length increased, while the DAI score, spleen index, and the expression levels of IL-6, IL-1β, TNF-α, TLR4, MyD88 and NF-κB p65 all decreased. Histopathological examination showed that treated UC rats' colon tissues closely resembled those of healthy controls. These findings indicate that pH-enzyme-responsive coated gel microspheres can effectively target the colon and show potential for UC treatment.

Silk-based biomaterials for tissue engineering

Tissue engineering (TE) involves repairing, replacing, regeneration, or improving the function of tissues and organs by combining cells, growth factors and scaffold materials. Among these, scaffold materials play a crucial role. Silk fibroin (SF), a natural biopolymer, has been widely used in the TE field due to its good biodegradability, biocompatibility, and mechanical properties attributed to its chemical composition and structure. This paper reviews the structure, extraction, and modification methods of SF. In addition, it discusses SF's regulation of cell behavior and its various processing modes. Finally, the applications of SF in TE and perspectives on future developments are presented. This review provides comprehensive and alternative rational insights for further biomedical translation in SF medical device design, further revealing the great potential of SF biomaterials.

Development of a multi-functional naringin-loaded bioglass/carboxymethyl chitosan/silk fibroin porous scaffold for hemostasis and critical size bone regeneration

Persistent bleeding and limited repair capacity greatly threaten patients with bone destruction. Designing inorganic-organic biomimetic scaffolds with quick hemostasis and osteogenesis functions will solve this problem. A novel degradable and naringin (NG) loaded porous scaffold (SCB-N) based on APTES-modified bioactive glass (ABG), carboxymethyl chitosan and silk fibroin is developed. ABG and NG enhance the strength of the scaffolds. The scaffolds can release NG and bioactive ions (Ca2+ and Si4+), promoting the expression of osteogenesis (OCN, BMP-2), angiogenesis (VEGF), and neurogenesis (TB3, GFAP) genes in bone mesenchymal stem cells (BMSCs) and the related proteins (OCN, BMP-2, VEGF, GFAP). When implanting the scaffolds in rat cranial critical size defects, all scaffolds exhibit good compatibility, and SCB-N2 (with ABG and 1 mg/mL NG) group significantly promotes new bone regeneration and the formation of M2-type macrophages. Transcriptome sequencing results confirmed the osteogenic differentiation of BMSCs stimulated by SCB-N2 scaffolds is mainly regulated through MAPK and Wnt signaling pathways. Moreover, SCB-N2 group demonstrates quick hemostasis in vitro and in vivo due to the high adsorption ability and Ca ions release. The novel bionic scaffolds loaded with ion/traditional Chinese medicine monomer, possess the capabilities of hemostasis, neurovascularization, osteogenesis and immunomodulation, therefore exhibiting potential in bone repair.

Development of Thermosensitive Mucoadhesive Gel Based Encapsulated Lipid Microspheres as Nose-to-Brain Rivastigmine Delivery System

Alzheimer's disease (ALZ) is a neurodegenerative disease that damages neuronal cells and causes decline in cognitive abilities. Administration of cholinesterase inhibitor compounds is the primary choice in the treatment of ALZ, one of which is rivastigmine (RVT). Several routes of administration of RVT are available, such as oral and transdermal. However, in the oral route, RVT has low bioavailability, undergoes first-pass metabolism, and the presence of the blood-brain barrier (BBB) reduces the therapeutic concentration of RVT. The transdermal route is nonselective target in the brain. This study aims to combine thermosensitive mucoadhesive gel (TG) and lipid microspheres (LM) as a drug delivery system to improve the efficacy of RVT. Combining these will prevent systemic side effects of RVT and increase drug concentration in the brain. LM was formulated with varying concentrations of Compritol polymer. The results of LM evaluation showed the values of particle size, PDI, and %EE and %DL were 8.519 μm, 0.018 ± 0.004, 72.54%, and 76.43%, respectively. The TG formulation can provide a liquid form at room temperature (25 °C) and a gel at nasal temperature (35 °C). Hemolytic and HET-CAM tests confirmed TG RVT LM's safety for use. Ex vivo studies showed controlled and sustained release of TG RVT LM, and in vivo studies showed TG RVT LM a higher pharmacokinetic profile in the brain than oral formulations and injections. The Cmax was found to be 7.05 ± 0.55 μg/cm3, Tmax was 24 h, and AUC0-24, which is related to the effectiveness of brain targeting, was 225.73 μg/cm3. In conclusion, this study shows the successful development of TG RVT LM, as evidenced by improved drug delivery to the brain, which is characterized by higher concentrations of RVT in the brain compared with oral and injectable RVT, this delivery system shows potential as a future treatment for Alzheimer's disease.

A sustainable and efficient strategy for bioconverting naringin to L-rhamnose, 2R-naringenin, and kaempferol

The development of a sustainable and efficient bioconversion strategy is crucial for the full-component utilization of naringin. In this study, an engineering Pichia pastoris co-culture system was developed to produce L-rhamnose and 2S/2R-naringenin. By optimizing transformation conditions, the co-culture system could completely convert naringin while fully consuming glucose. The production of 2S/2R-naringenin reached 59.5 mM with a molar conversion of 99.2%, and L-rhamnose reached 59.1 mM with a molar conversion of 98.5%. In addition, an engineering Escherichia coli co-culture system was developed to produce 2R-naringenin and kaempferol from 2S/2R-naringenin. Maximal kaempferol production reached 1050 mg/L with a corresponding molar conversion of 99.0%, and 996 mg/L 2R-naringenin was accumulated. Finally, a total of 17.4 g 2R-naringenin, 18.0 g kaempferol, and 26.1 g L-rhamnose were prepared from 100 g naringin. Thus, this study provides a novel strategy for the production of value-added compounds from naringin with an environmentally safe process.

3D-Printed Biomimetic Hydroxyapatite Composite Scaffold Loaded with Curculigoside for Rat Cranial Defect Repair

The treatment of various large bone defects has remained a challenge for orthopedic surgeons for a long time. Recent research indicates that curculigoside (CUR) extracted from the curculigo plant exerts a positive influence on bone formation, contributing to fracture healing. In this study, we employed emulsification/solvent evaporation techniques to successfully fabricate poly(ε-caprolactone) nanoparticles loaded with curculigoside (CUR@PM). Subsequently, using three-dimensional (3D) printing technology, we successfully developed a bioinspired composite scaffold named HA/GEL/SA/CUR@PM (HGSC), chemically cross-linked with calcium chloride, to ensure scaffold stability. Further characterization of the scaffold's physical and chemical properties revealed uniform pore size, good hydrophilicity, and appropriate mechanical properties while achieving sustained drug release for up to 12 days. In vitro experiments demonstrated the nontoxicity, good biocompatibility, and cell proliferative properties of HGSC. Through alkaline phosphatase (ALP) staining, Alizarin Red S (ARS) staining, cell migration assays, tube formation assays, and detection of angiogenic and osteogenic gene proteins, we confirmed the HGSC composite scaffold's significant angiogenic and osteoinductive capabilities. Eight weeks postimplantation in rat cranial defects, Micro-computed tomography (CT) and histological observations revealed pronounced angiogenesis and new bone growth in areas treated with the HGSC composite scaffold. These findings underscore the scaffold's exceptional angiogenic and osteogenic properties, providing a solid theoretical basis for clinical bone repair and demonstrating its potential in promoting vascularization and bone regeneration.

Recent advances of silk fibroin materials: From molecular modification and matrix enhancement to possible encapsulation-related functional food applications

Silk fibroin materials are emergingly explored for food applications due to their inherent properties including safe oral consumption, biocompatibility, gelatinization, antioxidant performance, and mechanical properties. However, silk fibroin possesses drawbacks like brittleness owing to its inherent specific composition and structure, which limit their applications in this field. This review discusses current progress about molecular modification methods on silk fibroin such as extraction, blending, self-assembly, enzymatic catalysis, etc., to address these limitations and improve their physical/chemical properties. It also summarizes matrix enhancement strategies including freeze drying, spray drying, electrospinning/electrospraying, microfluidic spinning/wheel spinning, desolvation and supercritical fluid, to generate nano-, submicron-, micron-, or bulk-scale materials. It finally highlights the food applications of silk fibroin materials, including nutraceutical improvement, emulsions, enzyme immobilization and 3D/4D printing. This review also provides insights on potential opportunities (like safe modification, toxicity risk evaluation, and digestion conditions) and possibilities (like digital additive manufacturing) in functional food industry.

Phytochemical Properties, Extraction, and Pharmacological Benefits of Naringin: A Review

This review describes the various innovative approaches implemented for naringin extraction as well as the recent developments in the field. Naringin was assessed in terms of its structure, chemical composition, and potential food sources. How naringin works pharmacologically was discussed, including its potential as an anti-diabetic, anti-inflammatory, and hepatoprotective substance. Citrus flavonoids are crucial herbal additives that have a huge spectrum of organic activities. Naringin is a nutritional flavanone glycoside that has been shown to be effective in the treatment of a few chronic disorders associated with ageing. Citrus fruits contain a common flavone glycoside that has specific pharmacological and biological properties. Naringin, a flavone glycoside with a range of intriguing characteristics, is abundant in citrus fruits. Naringin has been shown to have a variety of biological, medicinal, and pharmacological effects. Naringin is hydrolyzed into rhamnose and prunin by the naringinase, which also possesses l-rhamnosidase activity. D-glucosidase subsequently catalyzes the hydrolysis of prunin into glucose and naringenin. Naringin is known for having anti-inflammatory, antioxidant, and tumor-fighting effects. Numerous test animals and cell lines have been used to correlate naringin exposure to asthma, hyperlipidemia, diabetes, cancer, hyperthyroidism, and osteoporosis. This study focused on the many documented actions of naringin in in-vitro and in-vivo experimental and preclinical investigations, as well as its prospective therapeutic advantages, utilizing the information that is presently accessible in the literature. In addition to its pharmacokinetic characteristics, naringin's structure, distribution, different extraction methods, and potential use in the cosmetic, food, pharmaceutical, and animal feed sectors were discussed.

Developments in molecular docking technologies for application of polysaccharide-based materials: A review

With the increasing pollution of the planet, the search for natural multifunctional alternatives to petroleum-based plastics has assumed to be a great important proposition. Polysaccharides, an inexhaustible natural resource with good biocompatibility as well as mechanical properties, are considered as an ideal alternative to petroleum-based materials. However, blind experimentation and development will inevitably lead to waste of raw materials and contamination of reagents. Therefore, researchers desire a technology which can assist in predicting and screening experimental materials at the higher level. Molecular docking simulations, an emerging computer technology that can effectively predict the structure of interactions between molecules and analyze the optimal conformation, are a common aid for materials and drug design. In this review, we describe the origins and development of molecular docking techniques, mainly performed an overview of various molecular docking software on their applications in the field of different polysaccharide materials.

Controlled released naringin-loaded liposome/sucrose acetate isobutyrate hybrid depot for osteogenesis in vitro and in vivo

Introduction: A common problem in bone tissue engineering is that the burst release of active osteogenic factors is not beneficial for osteogenesis. This study aimed to prepare naringin (Ng) liposomes to reduce the burst release of Ng and improve new bone formation. Methods: We synthesized Ng liposomes using the thin-film hydration method. Drug-encapsulation efficacy experiments were conducted using the ultracentrifugation technique. The morphology and size distributions of freezedried liposomes were determined by transmission electron microscopy and dynamic light scattering. The Ng liposomes and Ng-lipo/sucrose acetate isobutyrate (SAIB) depots were characterized using Fourier transform infrared spectroscopy and in vitro release studies. After implantation of the Ng-lipo/SAIB depots, in vitro osteoblast-liposome interactions and in vivo osteogenesis were tested. Results: The formulation of freeze-dried Ng liposomes via an optimized recipe yielded nanosized (136.9 nm) negatively charged particles with a high encapsulation efficiency (~76.3%). Their chemical structure did not change after adding SAIB to the Ng liposomes. The burst release was reduced dramatically from 74.4% to 23.7%. In vivo, after 8 weeks, the new bone formation rate in the calvarial defects of Sprague-Dawley rats receiving Ng-lipo/SAIB was 57% compared with 25.18% in the control group (p = .0003). Discussion: Our results suggested that Ng-lipo/SAIB hybrid depots could serve as candidate materials for drug delivery in bone regeneration applications.