Electrospun core-shell structured nanofilm as a novel colon-specific delivery system for protein

Co-encapsulation of curcumin and fucoxanthin in solid-in-oil-in-water multilayer emulsions: Characterization, stability and programmed sequential release

To enhance the bioavailability of bioactives with varying efficacy in the gastrointestinal tract (GIT), a co-delivery system of solid-in-oil-in-water (S/O/W) emulsion was designed for the co-encapsulation of two bioactives in this paper. S/O/W emulsions were fabricated utilizing fucoxanthin (FUC)-loaded nanoparticles (NPs) as the solid phase, coconut oil containing curcumin (Cur) as the oil phase, and carboxymethyl starch (CMS)/propylene glycol alginate (PGA) complex as the aqueous phase. The high entrapment efficiency of Cur (82.3-91.3%) and FUC (96.0-96.1%) was found in the CMS/PGA complex-stabilized S/O/W emulsions. Encapsulation of Cur and FUC within S/O/W emulsions enhanced their UV and thermal stabilities. In addition, S/O/W emulsions prepared with CMS/PGA complexes displayed good stability. More importantly, the formed S/O/W emulsion possessed programmed sequential release characteristics, delivering Cur and FUC to the small intestine and colon, respectively. These results contributed to designing co-delivery systems for the programmed sequential release of two hydrophobic nutrients in the GIT.

Alginate-Based Electrospun Nanofibers and the Enabled Drug Controlled Release Profiles: A Review

Alginate is a natural polymer with good biocompatible properties and is a potential polymeric material for the sustainable development and replacement of petroleum derivatives. However, the non-spinnability of pure alginate solutions has hindered the expansion of alginate applications. With the continuous development of electrospinning technology, synthetic polymers, such as PEO and PVA, are used as co-spinning agents to increase the spinnability of alginate. Moreover, the coaxial, parallel Janus, tertiary and other diverse and novel electrospun fiber structures prepared by multi-fluid electrospinning have found a new breakthrough for the problem of poor spinning of natural polymers. Meanwhile, the diverse electrospun fiber structures effectively achieve multiple release modes of drugs. The powerful combination of alginate and electrostatic spinning is widely used in many biomedical fields, such as tissue engineering, regenerative engineering, bioscaffolds, and drug delivery, and the research fever continues to climb. This is particularly true for the controlled delivery aspect of drugs. This review provides a brief overview of alginate, introduces new advances in electrostatic spinning, and highlights the research progress of alginate-based electrospun nanofibers in achieving various controlled release modes, such as pulsed release, sustained release, biphasic release, responsive release, and targeted release.

Preparation of Eudragit S100-pullulan/hydroxypropyl-β-cyclodextrin complex-Eudragit S100 multilayer nanofiber film for resveratrol colon delivery

Cyclodextrin-based electrospun nanofibers are promising for encapsulating and preserving unstable compounds, but quick dissolution of certain nanofibers hinders their delivery application. In this study, hydroxypropyl-β-cyclodextrin (HPβCD) was used as an effective carrier of resveratrol (RSV) to obtain the RSV/HPβCD inclusion complex (HPIC), which was then incorporated into pullulan nanofibers. For enhancement of RSV release toward colon target, multilayer structure with a pullulan/HPIC film sandwiched between two layers of hydrophobic Eudragit S100 (ES100) nanofibers was employed. The relationship between the superiority of the ES100-pullulan/HPIC-ES100 film and its multilayer structure was verified. The intimate interactions of hydrogen bonds between two adjacent layers enhanced thermal stability, and the hydrophobic outer layers improved water contact resistance. According to release results, multilayer films also showed excellent colon-targeted delivery property and approximately 78.58 % of RSV was observed to release in colon stage. In terms of release mechanism, complex mechanism best described RSV colonic release. Additionally, ES100-pullulan/HPIC-ES100 multilayer films performed higher encapsulation efficiency when compared to the structures without HPIC, which further increased the antioxidant activity and total release amount of RSV. These results suggest a promising strategy for designing safe colonic delivery systems based on multilayer and HPIC structures with superior preservation for RSV.

Electrospun multi-chamber core-shell nanofibers and their controlled release behaviors: A review

Core-shell structure is a concentric circle structure found in nature. The rapid development of electrospinning technology provides more approaches for the production of core-shell nanofibers. The nanoscale effects and expansive specific surface area of core-shell nanofibers can facilitate the dissolution of drugs. By employing ingenious structural designs and judicious polymer selection, specialized nanofiber drug delivery systems can be prepared to achieve controlled drug release. The synergistic combination of core-shell structure and materials exhibits a strong strategy for enhancing the drug utilization efficiency and customizing the release profile of drugs. Consequently, multi-chamber core-shell nanofibers hold great promise for highly efficient disease treatment. However, little attention concentration is focused on the effect of multi-chamber core-shell nanofibers on controlled release of drugs. In this review, we introduced different fabrication techniques for multi-chamber core-shell nanostructures, including advanced electrospinning technologies and surface functionalization. Subsequently, we reviewed the different controlled drug release behaviors of multi-chamber core-shell nanofibers and their potential needs for disease treatment. The comprehensive elucidation of controlled release behaviors based on electrospun multi-chamber core-shell nanostructures could inspire the exploration of novel controlled delivery systems. Furthermore, once these fibers with customizable drug release profiles move toward industrial mass production, they will potentially promote the development of pharmacy and the treatment of various diseases. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Polysaccharides and proteins-based bionanocomposites for microencapsulation of probiotics to improve stability and viability in the gastrointestinal tract: A review

Probiotics have recently received significant attention due to their various benefits, such as the modulation of gut flora, reduction of blood sugar and insulin resistance, prevention and treatment of digestive disorders, and strengthening of the immune system. One of the major issues concerning probiotics is the maintenance of their viability in the presence of digestive conditions and extended shelf life during storage. To address this concern, numerous techniques have been explored to achieve success. Among these methods, the microencapsulation of probiotics has been proposed as the most effective way to overcome this challenge. The combination of nanomaterials with biopolymer coating is considered a novel approach to improve its viability and effective delivery. The use of polysaccharides and proteins-based bionanocomposites for microencapsulation of probiotics has emerged as an efficient and promising approach for maintaining cell viability and targeted delivery. This review article aims to investigate the use of different bionanocomposites in microencapsulation of probiotics and their effect on cell survival in long-term storage and harsh conditions in the gastrointestinal tract.

An efficient co-delivery system based on multilayer structural nanoparticles for programmed sequential release of resveratrol and vitamin D3 to combat dextran sodium sulfate-induced colitis in mice

Multilayer structural nanoparticles (MSNPs) fabricated by layer-by-layer self-assembly were used for the co-encapsulation of resveratrol (Res) and vitamin D3 (Vd). Res and Vd co-encapsulated MSNPs (Res-Vd-MSNPs) were evaluated by appearance, morphology, particle size, ζ potential and encapsulation efficiency (EE). The results showed that Res-Vd-MSNPs were spherical in shape with a particle size of 625.4 nm and a surface charge of +26.1 mV. The EE of Res and Vd was as high as 93.6 % and 90.8 %, respectively. Res-Vd-MSNPs exhibited better stability and lower degradation rate in simulated gastric fluid, allowing the programmed sequential release of Vd and Res in simulated intestinal fluid and simulated colonic fluid, which was also confirmed by in vivo fluorescence imaging of mice. In addition, Res-Vd-MSNPs effectively alleviated the clinical symptoms of dextran sulfate sodium salt (DSS)-induced colitis in mice, including weight loss, diarrhea and fecal bleeding, and it especially exerted a preventive effect on DSS-induced colon tissue damage and colon shortening. Furthermore, Res-Vd-MSNPs suppressed the expression of anti-inflammatory cytokines such as TNF-α, IL-1β and IL-6 and ameliorated DSS-induced oxidative damage, decreased colonic myeloperoxidase (MPO) and nitric oxide (NO) activities and elevated glutathione (GSH) level in DSS-treated mice. This study illustrated that MSNPs were potential carriers for developing the co-delivery system for the synergistic prevention and treatment of ulcerative colitis.

Construction and efficacy evaluation of chitosan-based nanoparticles for colon-targeted release of linoleic acid in rat pups

Long chain fatty acids in the colon play important roles in infant development. This study aimed to establish a colon-targeted long chain fatty acid release system in rat pups, with linoleic acid (LA) as the target model. LA-loaded chitosan nanoparticles (LA-CS NPs) synthesized via ionic crosslinkage showed spherical surface morphology and favorable encapsulation efficiency (84.96 %). In vivo distribution studies of LA-CS NPs demonstrated a significant increase in LA concentration in the colonic content after a 12-hour administration period. Additionally, oral administration of the delivery system (CS NPs: 18 μg/g/d, LA-CS NPs: 24 μg/g/d) exhibited no detrimental effects on the health of rat pups. In conclusion, this study presents a promising strategy for the targeted delivery of fatty acid to the colon in rat pups.

Alginate biopolymeric structures: Versatile carriers for bioactive compounds in functional foods and nutraceutical formulations: A review

Alginate-based biopolymer products have gained attention for protecting and delivering bioactive components in nutraceuticals and functional foods. These naturally abundant anionic, unbranched, and linear copolymers are also produced commercially by microorganisms. Alone or in combination with other copolymers, they efficiently transport bioactive molecules in food and nutraceutical products. This review aims to provide an in-depth understanding of alginate-based products and structures, emphasizing their role in delivering functional molecules in various formulations and delivery systems. These include edible coatings/films, gels/emulsions, beads/droplets, microspheres/particles, and engineered nanostructures where alginates have been used potentially. By exploring these applications, readers gain insights into the benefits of these products. Because, alginate-based biopolymer products have shown promise in delivering bioactive compounds like vitamin C, vitamin D3, curcumin, β-carotene, resveratrol, folic acid, gliadins, caffeic acid, betanin, limonoids, quercetin, several polyphenols and essential oils, etc., which are chief contributors to treating specific/overall nutritional and chronic metabolic disorders. So, this review summarizes the potential of alginate-based structures/products in various forms for delivering a wide range of functional food ingredients and nutraceutical components that offer promising perspectives for future investigations.

Poly-ε-caprolactone (PCL)/poly-l-lactic acid (PLLA) nanofibers loaded by nanoparticles-containing TGF-β1 with linearly arranged transforming structure as a scaffold in cartilage tissue engineering

This study aimed to present a novel three-dimensional nanocomposite scaffold using poly-ε-caprolactone (PCL), containing transforming growth factor-beta 1 (TGF-β1)-loaded chitosan-dextran nanoparticles and poly-l-lactic acid (PLLA), to make use of nanofibers and nanoparticles simultaneously. The electrospinning method fabricated a bead-free semi-aligned nanofiber composed of PLLA, PCL, and chitosan-dextran nanoparticles containing TGF-β1. A biomimetic scaffold was constructed with the desired mechanical properties, high hydrophilicity, and high porosity. Transmission electron microscopy findings showed a linear arrangement of nanoparticles along the core of fibers. Based on the results, burst release was not observed. The maximum release was achieved within 4 days, and sustained release was up to 21 days. The qRT-PCR results indicated an increase in the expression of aggrecan and collagen type Ι genes compared to the tissue culture polystyrene group. The results indicated the importance of topography and the sustained release of TGF-β1 from bifunctional scaffolds in directing the stem cell fate in cartilage tissue engineering.

Colon-Targeted Delivery of Indole Acetic Acid Helps Regulate Gut Motility by Activating the AHR Signaling Pathway

Intestinal peristalsis is vital for gastrointestinal physiology and host homeostasis and is frequently dysregulated in intestinal disorders. Gut microbiota can regulate gut motility, especially through the tryptophan metabolism pathway. However, the role of indoles as microbial tryptophan metabolites in colonic function requires further exploration. Here, we show that the delivery of indole acetic acid (IAA) targeting the colon can improve gut motility by activating the aryl hydrocarbon receptor (AHR). To achieve colon-targeted delivery, Eudragit S-100 (ES) and chitosan (CS) were used as drug carriers. After optimisation, IAA-loaded ES-coated CS nanoparticles exhibited an encapsulation efficiency of 83% and a drug-loading capacity of 16%. These nanoparticles exhibited pH-dependent characteristics and remained stable in acidic conditions and the upper intestine. In simulated intestinal fluid (pH 7.4) and colonic lumen, considerable amounts of IAA were released after approximately 4 h. Compared with free IAA, the nanoparticles exerted enhanced therapeutic effects on gut movement disorders induced by loperamide. The efficacy of IAA treatment was attributable to the activation of the AHR signalling pathway and increased levels of AHR agonists. Furthermore, the oral administration of IAA-loaded nanoparticles promoted serotonin secretion and maintained the intestinal barrier function. The experimental outcomes demonstrate the efficiency of the proposed colon-specific delivery system and highlight the role of IAA, produced by gut microbiota metabolism, in regulating gut peristalsis through AHR activation.

Nanostructured steady-state nanocarriers for nutrients preservation and delivery

Food bioactives possess specific physiological benefits of preventing certain diet-related chronic diseases or maintain human health. However, the limitations of the bioactives are their poor stability, lower water solubility and unacceptable bioaccessibility. Structure damage or degradation is often found for the bioactives under certain environmental conditions like high temperature, strong light, extreme pH or high oxygen concentration during food processing, packaging, storage and absorption. Nanostructured steady-state nanocarriers have shown great potential in overcoming the drawbacks for food bioactives. Various delivery systems including solid form delivery system, liquid form delivery system and encapsulation technology have been developed. The embedded food nutrients can largely decrease the loss and degradation during food processing, packaging and storage. The design and application of stimulus and targeted delivery systems can improve the stability, bioavailability and efficacy of the food bioactives upon oral consumption due to enzymatic degradation in the gastrointestinal tract. The food nutrients encapsulated in the smart delivery system can be well protected against degradation during oral administration, thus improving the bioavailability and releazing controlled or targeted release for food nutrients. The encapsulated food bioactives show great potential in nutrition therapy for sub-health status and disease. Much effort is required to design and prepare more biocompatible nanostructured steady-state nanocarriers using food-grade protein or polysaccharides as wall materials, which can be used in food industry and maintain the human health.

Effect of carboxymethyl konjac glucomannan coating on the stability and colon-targeted delivery performance of fucoxanthin-loaded gliadin nanoparticles

Fucoxanthin (FUC) is a hydrophobic carotenoid that has a protective effect on the colon. To exert the beneficial effects of FUC in the colon and expand its application in functional food, FUC was encapsulated in carboxymethyl konjac glucomannan (CMKGM)-coated gliadin nanoparticles (Gli-CMKGM NPs) in this paper. Gli-CMKGM NPs were prepared at pH 5.0 with Gli/CMKGM mass ratio of 1:1. The formation of Gli-CMKGM NPs was associated with hydrogen bonding, hydrophobic interactions and electrostatic attractions. Additionally, Gli-CMKGM NPs exhibited good stability to pH, salt, heating and storage. The results showed that FUC had been successfully encapsulated in Gli-CMKGM NPs, and the encapsulation efficiency of FUC-Gli-CMKGM NPs was significantly higher than that of uncoated FUC-Gli NPs. FUC-Gli-CMKGM NPs had a nano-spherical structure, and embedded FUC in Gli-CMKGM NPs improved their stabilities to photodegradation and thermal degradation. Furthermore, in vitro release and in vivo organ distribution studies showed that FUC-Gli-CMKGM NPs had an excellent colon targeting function. Overall, our findings illustrated the promise of CMKGM-coated Gli NPs for constructing targeted delivery systems for FUC.

Formulation of Levocetirizine-Loaded Core–Shell Type Nanofibrous Orally Dissolving Webs as a Potential Alternative for Immediate Release Dosage Forms

Several applications of nanofiber-based systems are based on their corresponding functionality-related properties, which often cannot be satisfied by a fiber web with a monolithic structure because of the various physicochemical properties and amounts of embedded compounds. Therefore, one of the main directions in the development of fiber systems is creating core–shell type complex fiber structures that can provide application-specific properties to the fiber matrix. The present study aimed to formulate levocetirizine-loaded core–shell type hydrophilic polymer-based fibrous systems. The core phase contained the antihistamine levocetirizine, while the permeation enhancer (Na-taurocholate), the local pH regulator (citric acid), and the cyclodextrin used as a taste masking agent were included in the shell phase of the fibrous formulation. Scanning electron microscopy images indicated that a randomly oriented homogeneous fibrous structure was obtained, while the Raman mapping and chemometric analysis confirmed the partially formed core–shell structure. A fast release rate of the antihistamine drug from the complex structural fibrous system was obtained (within 1 min complete dissolution can be observed) due to its increased surface area to volume ratio and its more favorable wettability properties, which consequently allows for more erosion. The masking properties against the unpleasant bitter taste of API of the formulated complex nanostructure were confirmed by the results of the electronic tongue. The formulated complex nanostructure enabled fast and complete release of the API, providing a potential enhancement in the rate and extent of absorption while masking the unpleasant taste of levocetirizine, which has a high impact on the patient adherence. All in all, the results show that the developed orally dissolving fibrous web formulation can be a potential alternative to the commercially available orally disintegrating tablets.

Chitosan-Tripolyphosphate Nanoparticles Prepared by Ionic Gelation Improve the Antioxidant Activities of Astaxanthin in the In Vitro and In Vivo Model

The present study aimed to investigate the effects of chitosan (CS)-tripolyphosphate (TPP) nanoparticles (NPs) on the stability, antioxidant activity, and bioavailability of astaxanthin (ASX). ASX-loaded CS-TPP NPs (ACT-NPs) prepared by ionic gelation between CS (0.571 mg/mL) and TPP (0.571 mg/mL) showed 505.2 ± 184.8 nm, 20.4 ± 1.2 mV, 0.348 ± 0.044, and 63.9 ± 3.0% of particle size, zeta potential, polydispersity index and encapsulation efficiency, respectively. An in vitro release study confirmed that the release of ASX in simulated gastric (pH 1.2) and intestinal (pH 6.8) fluid was prolonged within ACT-NPs. The in vitro antioxidant activities of ACT-NPs were significantly improved compared with free ASX (FA) (p < 0.05). Furthermore, the cellular and in vivo antioxidant analysis verified that ACT-NPs could enhance the cytoprotective effects on the BHK-21 cell line and demonstrate sustained release properties, leading to prolonged residence time in the rat plasma. The results suggest that the stability, antioxidant properties, and bioavailability of ASX can be effectively enhanced through encapsulation within CS-TPP NPs.

Electrospun Nanofibers: Current Progress and Applications in Food Systems

Electrospinning has the advantages of simple manufacturing equipment, a low spinning cost, wide range of spinnable materials, and a controllable mild process, which can continuously fabricate submicron or nanoscale ultrafine polymer fibers without high temperature or high pressure. The obtained nanofibrous films may have a large specific surface area, unique pore structure, and easy-to-modify surface characteristics. This review briefly introduces the types and fiber structures of electrospinning and summarizes the applications of electrospinning for food production (e.g., delivery systems for functional food, filtration of beverages), food packaging (e.g., intelligent packaging, antibacterial packaging, antioxidant packaging), and food analysis (e.g., pathogen detection, antibiotic detection, pesticide residue detection, food compositions analysis), focusing on the advantages of electrospinning applications in food systems. Furthermore, the limitations and future research directions of the technique are discussed.

Reinforced electrospun nanofiber composites for drug delivery applications

Electrospun technology becomes a valuable means of fabricating functional polymeric nanofibers with distinctive morphological properties for drug delivery applications. Nanofibers are prepared from the polymer solution, which allows the direct incorporation of therapeutics such as small drug molecules, genes, and proteins by merely mixing them into the polymeric solution. Due to their biocompatibility, adhesiveness, sterility, and efficiency in delivering diverse cargoes, electrospun nanofibers have gained much attention. This review discusses the capabilities of the electrospun nanofibers in delivering different therapeutics like small molecules, genes, and proteins to their desired target site for treating various ailments. The potential of nanofibers in administering through multiple administration routes and the associated challenges has also been expounded along with a cross-talk about the commercial products of nanofibers for biomedical applications.

A colon-targeted podophyllotoxin nanoprodrug: synthesis, characterization, and supramolecular hydrogel formation for the drug combination

Making full use of the undeveloped bioactive natural product derivatives by selectively delivering them to target sites can effectively increase their druggability and reduce the wastage of resources. Azo-based prodrugs are widely regarded as an effective targeted delivery means for colon-related disease treatment. Herein, we report a new-type of azo-based nanoprodrug obtained from bioactive natural products, in which the readily available podophyllotoxin natural products are connected with methoxy polyethylene glycol (mPEG) via a multifunctional azobenzene group. The amphiphilic prodrug can form nanosized micelles in water and will be highly selectively activated by azoreductases, leading to the in situ generation of anticancer podophyllotoxin derivatives (AdP) in the colon after the cleavage of the azo bond. To satisfy the demand of drug carriers for cancer combination therapy in clinics, α-CD is further introduced into this nanoprodrug micelle system to form a supramolecular hydrogel via a cascade self-assembly strategy. Using imaging mass spectrometry (IMS), the colon-specific drug release ability of the hydrogel after oral administration is demonstrated at the molecular level. Finally, the nanoprodrug hydrogel is further used as a carrier to load a hydrophilic anti-cancer drug 5-FU during the hierarchical self-assembly process and to co-deliver AdP and 5-FU for the drug combination. The combination use of AdP and 5-FU provides enhanced cytotoxicity which indicates a significant synergistic interaction. This work offers a new way to enhance the therapeutic effect of nanoprodrugs via drug combination, and provides a new strategy for reusing bioactive natural products and their derivatives.

Oral fate and stabilization technologies of lactoferrin: a systematic review

Lactoferrin (Lf), a bioactive protein initially found in many biological secretions including milk, is regarded as the nutritional supplement or therapeutic ligand due to its multiple functions. Research on its mode of action reveals that intact Lf or its active peptide (i.e., lactoferricin) shows an important multifunctional performance. Oral delivery is considered as the most convenient administration route for this bioactive protein. Unfortunately, Lf is sensitive to the gastrointestinal (GI) physicochemical stresses and lactoferricin is undetectable in GI digesta. This review introduces the functionality of Lf at the molecular level and its degradation behavior in GI tract is discussed in detail. Subsequently, the absorption and transport of Lf from intestine into the blood circulation, which is pivotal to its health promoting effects in various tissues, and some assisting labeling methods are discussed. Stabilization technologies aiming at preserving the structural integrity and functional properties of orally administrated Lf are summarized and compared. Altogether, this work comprehensively reviews the structure-function relationship of Lf, its oral fate and the development of stabilization technologies for the enhancement of the oral bioavailability of Lf. The existing limitations and scope for future research are also discussed.

A tunable temperature-responsive and tough platform for controlled drug delivery

A tunable temperature-responsive site-specific drug-delivery platform for tumor therapy.

Micro and nanoscale technologies in oral drug delivery

Oral administration is a pillar of the pharmaceutical industry and yet it remains challenging to administer hydrophilic therapeutics by the oral route. Smart and controlled oral drug delivery could bypass the physiological barriers that limit the oral delivery of these therapeutics. Micro- and nanoscale technologies, with an unprecedented ability to create, control, and measure micro- or nanoenvironments, have found tremendous applications in biology and medicine. In particular, significant advances have been made in using these technologies for oral drug delivery. In this review, we briefly describe biological barriers to oral drug delivery and micro and nanoscale fabrication technologies. Micro and nanoscale drug carriers fabricated using these technologies, including bioadhesives, microparticles, micropatches, and nanoparticles, are described. Other applications of micro and nanoscale technologies are discussed, including fabrication of devices and tissue engineering models to precisely control or assess oral drug delivery in vivo and in vitro, respectively. Strategies to advance translation of micro and nanotechnologies into clinical trials for oral drug delivery are mentioned. Finally, challenges and future prospects on further integration of micro and nanoscale technologies with oral drug delivery systems are highlighted.

Design and application of oral colon administration system

Oral colon administration system has become a new method to treat intestinal diseases. The implementation of colon drug delivery system is restricted by many aspects, including physical and chemical properties, drug delivery mode, gastrointestinal physiological factors, and so on. Delivery methods to overcome these challenges revolve around the mechanisms of drug delivery, including the use of rational dosage forms to avoid the complex pH environment, and the prevention of drug release and absorption in the upper digestive tract.

Targeted delivery of phycocyanin for the prevention of colon cancer using electrospun fibers

Phycocyanin (PC), a water-soluble biliprotein, exhibits potent anti-colon cancer properties. However, its application in functional foods is limited by the poor stability and low bioavailability of PC. In this study, we successfully encapsulated PC by coaxial electrospinning. The colon targeted release of PC was achieved with retention of the antioxidant activity of PC. The PC-loaded electrospun fiber mat (EFM) obtained inhibited HCT116 cell growth in a dose-dependent and time-dependent manner. In particular, the PC-loaded EFM exerted its anti-cancer activity by blocking the cell cycle at the G0/G1 phase and inducing cell apoptosis involving the decrease of Bcl-2/Bax, activation of caspase 3 and release of cytochrome c. This study suggests that co-axial electrospinning is an efficient and effective way to deliver PC and improve its bioavailability; thus, it represents a promising approach for encapsulating functional ingredients for colon cancer prevention.

Preparation and Characterization of Electrospun Colon-Specific Delivery System for Quercetin and Its Antiproliferative Effect on Cancer Cells

To improve the oral bioavailability of quercetin (Q) and achieve colon-specific release, a core-sheath electrospun fiber mat containing Q-loaded chitosan nanoparticle (Q-loaded EFM) was developed in this study. The nanoparticle was first fabricated, and its antioxidant activity was as effective as free Q. Then the uniform Q-loaded EFM was obtained using response surface methodology optimization, and its core-sheath structure was characterized by confocal laser scanning microscopy. In vitro release kinetics confirmed the colon targeting profile, and the release rate of Q varied inversely with fiber diameter. The data of Cell Counting Kit-8 suggested Q-loaded EFM inhibited the proliferation of Caco-2 cells in a dose- and time-dependent manner with an IC50 of 4.36, 2.81, and 2.01 mg/mL after 24, 48, and 72 h, respectively, and it was caused by arresting cell cycle on G₀/G₁ phase and triggering apoptotic cell death. This study suggests that the Q-loaded EFM represents a promising form in the oral therapy of colon disorders.

Improved Viability and Thermal Stability of the Probiotics Encapsulated in a Novel Electrospun Fiber Mat

For the enhancement of the probiotics' survivability, a nanostructured fiber mat was developed by electrospinning. The probiotic Lactobacillus plantarum was encapsulated in the nanofibers with fructooligosaccharides (FOS) as the cell material. Fluorescence microscope image and scanning electron microscopy (SEM) showed that viable cells were successfully encapsulated in nanofibers (mean diameter = 410 ± 150 nm), and the applied voltage had no significant influence on their viability ( P > 0.05). A significantly improved viability (1.1 log) was achieved by incorporating 2.5% (w/w) of FOS as the electrospinning material ( P < 0.001). Additionally, compared with free cells, the survivability of cells encapsulated in electrospun FOS/PVA/ L. plantarum nanofibers was significantly enhanced under moist heat treatment (60 and 70 °C). This study shows that the obtained nanofiber is a feasible entrapment structure to improve the viability and thermal stability of encapsulated probiotic cells and provides an alternative approach for the development of functional food.

Localized Controlled Delivery of Gemcitabine via Microsol Electrospun Fibers to Prevent Pancreatic Cancer Recurrence

The low radical surgery rate of pancreatic cancer leads to increased local recurrence and poor prognosis. Gemcitabine (GEM) is the preferred chemotherapeutic for pancreatic cancer. However, systemic chemotherapy with GEM has reached a bottleneck due to its serious side effects after frequent injections. In this study, GEM is successfully enwrapped into electrospun fibers via microsol electrospinning technology to form a stable core-shell fibrous structure. The GEM release rate can be adjusted by altering the thickness of the hyaluronan-sol inner fiber and the quantity of loaded GEM, and the release can be sustained for as long as three weeks. In vitro assays show that these electrospun fibers effectively inhibit pancreatic cancer cells and promote apoptosis. In vivo studies show that the fibrous membranes are better for inhibiting the growth of residual tumors than that of integrated tumors. Furthermore, immunohistochemistry results show that GEM-loaded fibers promote a higher cell apoptosis rate than does systemically injected GEM in residual tumors. In addition, the local delivery of GEM with fibers significantly reduces liver toxicity. In summary, a core-shell electrospun fiber for the controlled and localized delivery of GEM, which greatly improves the treatment of residual tumors and prevents pancreatic tumor recurrence, is developed.

A Novel Colon-Specific Osmotic Pump Capsule of Panax notoginseng Saponins (PNS): Formulation, Optimization, and In Vitro-In Vivo Evaluation

In the current study, a novel colon-specific osmotic pump capsule of Panax notoginseng saponins was developed to achieve colon-specific release, a zero-order, thus to promote the efficacy of Panax notoginseng saponins. The capsule was assembled using a semi-permeable capsule shell with contents including Panax notoginseng saponins, sodium chloride (NaCl), and Ludipress. The semipermeable membrane was made of cellulose acetate (CA), along with polyethylene glycol (PEG) 6000 for flexibility and strength, and Eudragit® S100 for colon-specific targeting. The in vitro dissolution test showed an approximately zero-order release of Panax notoginseng saponins over 12 h at pH 7.8 through the pores on the membrane. Meanwhile, the drug release from the optimal formulation was found to be independent of equipment type or agitation speed. Rather, it depended on mainly the osmotic pressure of the dissolution media. The in vivo test in beagle dogs demonstrated that the relative bioavailability of the current system was 487.42% in comparison to that of the marketed product, yet with a prolonged retention time. The novel controlled delivery system for Panax notoginseng saponins in the current study utilizing colon-specific and osmotic pump system therefore offered the advantages of avoiding stomach and enteric irritation, reducing dosage frequency, minimizing the drug fluctuation in plasma, and improving its oral bioavailability.

Encapsulation of Bioactive Compound in Electrospun Fibers and Its Potential Application

Electrospinning is a simple and versatile encapsulation technology. Since electrospinning does not involve severe conditions of temperature or pressure or the use of harsh chemicals, it has great potential for effectively entrapping and delivering bioactive compounds. Recently, electrospinning has been used in the food industry to encapsulate bioactive compounds into different biopolymers (carbohydrates and proteins), protecting them from adverse environmental conditions, maintaining the health-promoting properties, and achieving their controlled release. Electrospinning opens a new horizon in food technology with possible commercialization in the near future. This review summarizes the principles and the types of electrospinning processes. The electrospinning of biopolymers and their application in encapsulating of bioactive compounds are highlighted. The existing scope, limitations, and future prospects of electrospinning bioactive compounds are also presented.

Preparation and Characterization of Protein-Loaded Electrospun Fiber Mat and Its Release Kinetics

For the enhancement of protein's bioavailability, a specific delivery system was developed by coaxial electrospinning. Bovine serum albumin (BSA) was used as protein model, and the core-sheath fiber mat was fabricated using sodium alginate as shell layer and the BSA-loaded chitosan nanoparticle that was prepared previously as core layer. By optimizing electrospinning parameters, uniform fibers with diameters ranging from 200-600 nm were obtained, and transmission electron microscopy and confocal laser scanning microscopy revealed their core-sheath structures. Fourier transform infrared spectroscopy (FTIR) analysis demonstrated that there existed molecular interaction between components, which enhanced the mat's thermal stability and mechanic property. It was found that the predominant release mechanism of BSA from fiber mat was erosion, and little change occurred in the secondary structure of encapsulated BSA indicated by FTIR and circular dichroism analysis. The study shows that the obtained fiber mat is a potential delivery system for protein.

Fabrication of aqueous-based dual drug loaded silk fibroin electrospun nanofibers embedded with curcumin-loaded RSF nanospheres for drugs controlled release

This paper presents a new nanofabrication method for dual drug loaded regenerated silk fibroin (RSF) nanofibers, based on a simple, colloid-electrospinning technique.