Preparation, characterization and in vitro evaluation of melatonin-loaded porous starch for enhanced bioavailability

Porous Starch-inulin Loaded Quercetin Microcapsules: Characterization, Antioxidant Activity, in-vitro Release, and Storage Stability

Quercetin (Q) has many potential health benefits, but its low stability limits its use in functional foods and pharmaceuticals. The low stability of quercetin is a challenge that needs to be addressed to fully realize its therapeutic potential. The purpose of this study was therefore to design a proper carrier based on porous starch (PS) and inulin (IN) in order to improve the stability of Q. The scanning electron microscopy (SEM) images denoted that the Q molecules were adsorbed in the PS pores and partially adhered to the surface of the granules. Both types of the wall material could remarkably enhance the protection of Q against thermal and light degradation. The retention index of Q under different environmental conditions was higher for the PS:IN-Q than PS-Q. The results of Fourier transform infrared spectroscopy (FT-IR) revealed that Q interacted with the wall materials through non-covalent bonds. X-ray diffraction (XRD) also confirmed the encapsulation of Q in the wall materials. The bonding between Q and the hydrogen groups of starch compacted the crystalline regions and increased the relative crystallinity in PS-Q and PS:IN-Q. The DPPH and ABTS scavenging activities of the microcapsules containing the PS and IN were higher than those of free Q. Examination of the in-vitro release profile indicated that the Q release rate was lower from the PS:IN-Q microcapsules (21.6%) than from the PS-Q ones (33.7%). Our findings highlight the significant potential of this novel biopolymer mixture (PS/IN) as a promising wall material for the protection and delivery of bioactive compounds.

Bioactive delivery systems based on starch and its derivatives: Assembly and application at different structural levels

Starch and modified starch, spanning various structural levels, are comprehensively reviewed, with a special emphasis on the advancement of starch and its derivative-based delivery systems for bioactive substances. The pivotal aspect highlighted is the controlled release of active ingredients by starch-based delivery systems with distinct hierarchical structures. At the molecular level, diverse categories of starch degradation products, such as dextrin and highly branched starch, serve as versatile amphiphilic carriers for encapsulating active ingredients. At the level of helical structure, the distinctive configuration of the starch-guest complex partly determines the mechanism of controlled release for diverse active components. At the crystal and particle structural level, starch assumes the role of a carrier, effectively modulating the release of active substances, and enhances the innate physiological activity of different active components. As a natural polymer molecule, starch can also generate hydrogel materials in polymer form, expanding its utility in the fields of food, materials, and even medicine.

Expanded porous-starch matrix as an alternative to porous starch granule: Present status, challenges, and future prospects

Exposing the hydrated-soft-starch matrix of intact grain or reconstituted flour dough to a high-temperature-short-time (HTST) leads to rapid vapor generation that facilitates high-pressure build-up in its elastic matrix linked to large deformation and expansion. The expanded starch matrix at high temperatures dries up quickly by flash vaporization of water, which causes loss of its structural flexibility and imparts a porous and rigid structure of the expanded porous starch matrix (EPSM). EPSM, with abundant pores in its construction, offers adsorptive effectiveness, solubility, swelling ability, mechanical strength, and thermal stability. It can be a sustainable and easy-to-construct alternative to porous starch (PS) in food and pharmaceutical applications. This review is a comparative study of PS and EPSM on their preparation methods, structure, and physicochemical properties, finding compatibility and addressing challenges in recommending EPSM as an alternative to PS in adsorbing, dispersing, stabilizing, and delivering active ingredients in a controlled and efficient way.

Colon targeted releases and uptakes of paclitaxel loaded in modified porous starch

Hyaluronic acid can modify porous starch through cross-linking and hydrogen bonding, effectively achieving a paclitaxel entrapment efficiency of ∼92 % and drug loading of ∼23 %. In this study, the pores and intergranular gaps of porous starch were filled with paclitaxel under solvent volatilization, and the enrichment process and its characteristics were recorded using a microscope. The paclitaxel-loaded particles were coated with chitosan-phytic acid to target the colon. In vivo imaging in mice showed that the capsule released paclitaxel in the colon rather than in the upper digestive tract, and the paclitaxel distribution in the main organs at 24 h was significantly lower than that of raw paclitaxel. Hyaluronic acid-modified porous starch can target cancer cells. Cell internalization of paclitaxel mediated by hyaluronic acid was approximately 1.97 times that of raw paclitaxel, higher than that of receptor-shielded cells and cells incubated with unmodified carriers, as evidenced by the accumulation of fluorescent paclitaxel in the nucleus and marked cell apoptosis. The hyaluronic acid-modified porous starch system is an effective method for the high-load and targeted release of hydrophobic anticancer drugs.

Research progress of starch as microencapsulated wall material

Starch is non-toxic, low cost, and possesses good biocompatibility and biodegradability. As a natural polymer material, starch is an ideal choice for microcapsule wall materials. Starch-based microcapsules have a wide range of applications and application prospects in fields such as food, pharmaceuticals, cosmetics, and others. This paper firstly reviews the commonly used wall materials and preparation methods of starch-based microcapsules. Then the effect of starch wall materials on microcapsule properties is introduced in detail. It is expected to provide researchers with design inspiration and ideas for the development of starch-based microcapsules. Next the applications of starch-based microcapsules in various fields are presented. Finally, the future trends of starch-based microcapsules are discussed. Molecular simulation, green chemistry, and solutions to the main problems faced by resistant starch microcapsules may be the future research trends of starch-based microcapsules.

Oral delivery of porous starch-loaded bilayer microgels for controlled drug delivery and treatment of ulcerative colitis

We prepared one type of bilayer microgels for oral administration with three effects: pH responsiveness, time lag, and colon enzyme degradation. Combined with the dual biological effects of curcumin (Cur) for reducing inflammation and promoting repair of colonic mucosal injury, targeted colonic localization and release of Cur according to the colonic microenvironment were enhanced. The inner core, derived from guar gum and low-methoxyl pectin, afforded colonic adhesion and degradation behavior; the outer layer, modified by alginate and chitosan via polyelectrolyte interaction, achieved colonic localization. The porous starch (PS)-mediated strong adsorption allowed Cur loading in inner core to achieve a multifunctional delivery system. In vitro, the formulations exhibited good bioresponses at different pH conditions, potentially delaying Cur release in the upper gastrointestinal tract. In vivo, dextran sulfate sodium-induced ulcerative colitis (UC) symptoms were significantly alleviated after oral administration, accompanied by reduced levels of inflammatory factors. The formulations facilitated colonic delivery, allowing Cur accumulation in colonic tissue. Moreover, the formulations could alter gut microbiota composition in mice. During Cur delivery, each formulation increased species richness, decreased pathogenic bacterial content, and afforded synergistic effects against UC. These PS-loaded bilayer microgels, exhibiting excellent biocompatibility, multi-bioresponsiveness, and colon targeting, could be beneficial in UC therapy, allowing development into a novel oral formulation.

Preparation of starch-based functional food nano-microcapsule delivery system and its controlled release characteristics

Most of the functional substances in food are absorbed in the small intestine, but before entering the small intestine, the strong acid and enzymes in the stomach limit the amount that can reach the small intestine. Therefore, in this paper, to develop a delivery system for functional food ingredients, maintain the biological activity of the ingredients, and deliver them to the target digestive organs, preparation of starch-based functional food nano-microcapsule delivery system and its controlled release characteristics were reviewed. Embedding unstable food active ingredients in starch-based nano-microcapsules can give the core material excellent stability and certain functional effects. Starch-based wall materials refer to a type of natural polymer material that uses starch or its derivatives to coat fat-soluble components with its hydrophobic cavities. The preparation methods of starch-based wall materials mainly include spray drying, extrusion, freeze drying, ultra-high pressure, coagulation, fluidized bed coating, molecular inclusion, chemical, and enzymic methods. The controlled release of functional food can be achieved by preparing starch-based nano-microcapsules to encapsulate the active agents. It has been reported that that compared with traditional embedding agents such as gelatin, acacia gum, and xanthan gum, starch-based functional food nano-microcapsule delivery system had many good properties, including improving antioxidant capacity, bioavailability, probiotics, and concealing bad flavors. From this review, we can learn which method should be chosen to prepare starch-based functional food nano-microcapsule delivery system and understand the mechanism of controlled release.

Progress and prospects of modified starch-based carriers in anticancer drug delivery

Recently, the role of starch-based carrier systems in anticancer drug delivery has gained considerable attention. Although there are same anticancer drugs, difference in their formulations account for unique therapeutic effects. However, the exploration on the effect-enhancing of anticancer drugs and their loading system by modified starch from the perspective of carrier regulation is still limited. Moreover, research on the reduced toxicity of the anticancer drugs due to modified starch as the drug carrier mediated by the intestinal microenvironment is lacking, but worth exploring. In this review, we examined the effect of modified starch on the loading and release properties of anticancer drugs, and the effect of resistant starch and its metabolites on intestinal microecology during inflammation. Particularly, the interactions between modified starch and drugs, and the effect of resistant starch on gene expression, protein secretion, and inflammatory factors were discussed. The findings of this review could serve as reference for the development of anticancer drug carriers in the future.

Artemisinin hydroxypropyl-β-cyclodextrin inclusion complex loaded with porous starch for enhanced bioavailability

The current work aimed to enhance the oral bioavailability of water-insoluble drug Artemisinin (ART) by the inclusion of ART with hydroxypropyl-β-cyclodextrin (HP-β-CD) and then loaded with porous starch (PS). The preparation conditions of ART HP-β-CD inclusion complex loaded with PS (AHPS) were optimized according to drug loading (DL) and entrapment efficiency (EE). The properties of AHPS were characterized by optical and thermodynamic methods. ART was linked by hydrogen bond to HP-β-CD to form hydrophilic supramolecules, which are loaded into PS under the action of hydrogen bond. The maximum DL and EE of AHPS were about 16.51% and 67.26%, respectively. Then we investigated the physicochemical properties and antimalarial activity of AHPS. The solubility and bioavailability of AHPS at 48 h were higher than ART and market ART piperaquine tablets (APT), and showed better antimalarial activity in vitro and vivo. It provides a new idea for the development and application of fat-soluble drug.

Silk Fibroin Microneedle Patches for the Treatment of Insomnia

As a patient-friendly technology, drug-loaded microneedles can deliver drugs through the skin into the body. This system has broad application prospects and is receiving wide attention. Based on the knowledge acquired in this work, we successfully developed a melatonin-loaded microneedle prepared from proline/melatonin/silk fibroin. The engineered microneedles' morphological, physical, and chemical properties were characterized to investigate their structural transformation mechanism and transdermal drug-delivery capabilities. The results indicated that the crystal structure of silk fibroin in drug-loaded microneedles was mainly Silk I crystal structure, with a low dissolution rate and suitable swelling property. Melatonin-loaded microneedles showed high mechanical properties, and the breaking strength of a single needle was 1.2 N, which could easily be penetrated the skin. The drug release results in vitro revealed that the effective drug concentration was obtained quickly during the early delivery. The successful drug concentration was maintained through continuous release at the later stage. For in vivo experimentation, the Sprague Dawley (SD) rat model of insomnia was constructed. The outcome exhibited that the melatonin-loaded microneedle released the drug into the body through the skin and maintained a high blood concentration (over 5 ng/mL) for 4-6 h. The maximum blood concentration was above 10 ng/mL, and the peak time was 0.31 h. This system indicates that it achieved the purpose of mimicking physiological release and treating insomnia.

Construction, characterization, and bioavailability evaluation of honokiol-loaded porous starch by melting method without any solvent

In the present study, the porous starch (PS) was used as an efficient carrier of honokiol (HK), and the HK-loaded PS (HPS) delivery system was prepared by melting method without using organic solvents. Its physical-chemical properties, solubility and oral bioavailability were also investigated. The obtained results proved that the HK in the HPS was mostly amorphous when it was loaded into the PSs with 87.54 ± 1.52% of encapsulation efficiency (EE) and 12.51 ± 0.22% of drug loading (DL) capacity. The water-solubility of the HPS was increased to 115.27 ± 2.92 μg/mL (pH = 1.2, artificial gastric juice (AGJ)), 161.58 ± 3.42 (pH = 6.8, artificial intestinal juice (AIJ)) and 148.5 ± 1.89 μg/mL (pH = 5.5, simulated tumor microenvironment), being 6.07, 4.38 and 4.87-folds higher than free HK. In vitro dissolution tests showed the HK was significantly higher from HPS than from free HK. Furthermore, compared with free HK, the release rate and the bioavailability was also substantially improved for HK from the HPS. Meanwhile, the HPS generated a higher inhibition to HepG2 cells than free HK.

Foams as unique drug delivery systems

Foams are multiphase systems found throughout nature. We meet them equally often in our everyday life, starting with the foam in the morning espresso, where the foam should constitute 10% of the drink or in a glass of beer and ending with the evening bath with foam. These multiphase systems consist mainly of gas, which is separated by liquid or solid lamellae. The lamellae have a very large surface area and a small thickness, which results in their low stability. The foams in pharmaceutics are known for a long time as protective or therapeutic preparations for topical use. However, the physicochemical structure of both solid and liquid foams offers multiple fields of application in the modern therapy. For instance, owing to the unique structure, foams can be also used for parenteral use in the form of implants serving as a drug carrier and at the same time, a scaffold for regenerating the tissue. Foams can also be used orally in the form of controlled drug delivery systems that are potentially useful for sustained or targeted drug delivery. The article describes the unique advantages and features of foams that make them useful in modern pharmacotherapy.

Nanotechnology and Reproductive Management of Farm Animals: Challenges and Advances

Reproductive efficiency of farm animals has central consequences on productivity and profitability of livestock farming systems. Optimal reproductive management is based on applying different strategies, including biological, hormonal, nutritional strategies, as well as reproductive disease control. These strategies should not only guarantee sufficient reproductive outcomes but should also comply with practical and ethical aspects. For example, the efficiency of the biological- and hormonal-based reproductive strategies is mainly related to several biological factors and physiological status of animals, and of nutritional strategies, additional factors, such as digestion and absorption, can contribute. In addition, the management of reproductive-related diseases is challenged by the concerns regarding the intensive use of antibiotics and the development of antimicrobial resistant strains. The emergence of nanotechnology applications in livestock farming systems may present innovative and new solutions for overcoming reproductive management challenges. Many drugs (hormones and antibiotics), biological molecules, and nutrients can acquire novel physicochemical properties using nanotechnology; the main ones are improved bioavailability, higher cellular uptake, controlled sustained release, and lower toxicity compared with ordinary forms. In this review, we illustrate advances in the most common reproductive management strategies by applying nanotechnology, considering the current challenges of each strategy.

Melatonin in Cancer Treatment: Current Knowledge and Future Opportunities

Melatonin is a pleotropic molecule with numerous biological activities. Epidemiological and experimental studies have documented that melatonin could inhibit different types of cancer in vitro and in vivo. Results showed the involvement of melatonin in different anticancer mechanisms including apoptosis induction, cell proliferation inhibition, reduction in tumor growth and metastases, reduction in the side effects associated with chemotherapy and radiotherapy, decreasing drug resistance in cancer therapy, and augmentation of the therapeutic effects of conventional anticancer therapies. Clinical trials revealed that melatonin is an effective adjuvant drug to all conventional therapies. This review summarized melatonin biosynthesis, availability from natural sources, metabolism, bioavailability, anticancer mechanisms of melatonin, its use in clinical trials, and pharmaceutical formulation. Studies discussed in this review will provide a solid foundation for researchers and physicians to design and develop new therapies to treat and prevent cancer using melatonin.

Toxicology of Blister Agents: Is Melatonin a Potential Therapeutic Option?

Blister or vesicant chemical warfare agents (CWAs) have been widely used in different military conflicts, including World War I and the Iran-Iraq War. However, their mechanism of action is not fully understood. Sulfur and nitrogen mustard exert toxic effects not only through the alkylation of thiol-bearing macromolecules, such as DNA and proteins, but also produce free radicals that can develop direct toxic effects in target organs such as the eyes, skin, and respiratory system. The lack of effective treatments against vesicant CWAs-induced injury makes us consider, in this complex scenario, the use and development of melatonin-based therapeutic strategies. This multifunctional indoleamine could facilitate neutralization of the oxidative stress, modulate the inflammatory response, and prevent the DNA damage, as well as the long-term health consequences mediated by vesicant CWAs-induced epigenetic mechanisms. In this context, it would be essential to develop new galenic formulations for the use of orally and/or topically applied melatonin for the prophylaxis against vesicant CWAs, as well as the development of post-exposure treatments in the near future.

Preparation and characterization of selenium-rich polysaccharide from Phellinus igniarius and its effects on wound healing

The modified of polysaccharides show various bio-activities. In our work, Phellinus igniarius Selenium-enriched mycelias polysaccharides (PSeP) were prepared from Phellinus igniarius, and its antioxidant and anti-inflammatory effects on injured mice were evaluated. The selenium content and physical properties of polysaccharides were characterized by GC, HPGPC, and FT-IR analysis. The results showed that PSeP could reduce reactive oxygen species (ROS) levels, myeloperoxidase (MPO) activity as well as malondialdehyde (MDA) content. Meanwhile, it increased the enzyme activities of glutathione peroxidase (GSH-Px) and catalase (CAT). Finally, it showed obvious wound healing effects in vivo. Moreover, PSeP could clear the ROS without obvious cytotoxicity. PSeP could further improve its ability to clear ROS level to promote skin wound healing in mice three days in advance.

Encapsulation of caffeine into starch matrices: Bitterness evaluation and suppression mechanism

In this study, caffeine (CA) was encapsulated into food-grade starch matrices, including swelled starch (SS), porous starch (PS), and V-type starch (VS). The bitterness of the microcapsules and suppression mechanisms were investigated using an electronic tongue, molecular dynamics (MD) simulation and the in vitro release kinetics of CA. All the CA-loaded microcapsules showed a lower bitterness intensity than the control. The MD results proved that the weak interactions between starch and CA resulted in a moderate CA release rate for SS-CA microcapsules. The PS-CA microcapsule presented the longest CA release, up to 40 min, whereas the VS-CA microcapsule completely released CA in 9 min. The CA release rate was found to be related to the microcapsule structure and rehydration properties. A low CA bitterness intensity could be attributed to a delay in the CA release rate and resistance to erosion of the microcapsules. The results of this work are valuable for improving starch-based microcapsules (oral-targeted drug-delivery systems) by suppressing the bitterness of alkaloid compounds.

Fabrication of nanostructured mesoporous starch encapsulating soy-derived phytoestrogen (genistein) by well-tuned solvent exchange method

The present research was concerned with preparation of mesoporous starch (MPS) as a carrier for genistein, a model of poorly water-soluble phytoestrogen isoflavone; and exploration of the impact of different fabrication parameters on structural and loading properties. MPS is considered as a highly porous biomaterial which typically possesses nanometer-sized porous microstructure and low density, providing a large effective specific surface area (SSA) and hydrophilic surface to improve solubility, stability and bioavailability of poorly water-soluble active agents. To fabricate MPS, various concentrations (8-14% w/v) of starch from different sources (corn, potato and tapioca) was used for gel formation and the successive solvent exchange process was performed with use of various ethanol concentrations (40-70% v/v), which were then dried by different techniques (rotary vacuum evaporation, microwave and freeze drying). MPS quality attributes such as SSA, total porous volume, BJH pore diameter and swelling ratio were determined and effects of the fabrication parameters were investigated using L9-Taguchi orthogonal array design. The results indicate that second order polynomial regression models were well fitted for all response variables. Interestingly, the starch components greatly influenced physical properties of MPS. Also, the drying type and ethanol concentration altered significantly the model equations. The overall best fabrication condition (14% corn starch, 100% ethanol concentration in aging step and rotary vacuum drying) resulted in favorable MPS preparation with mean size of 105.4 nm and unimodal distribution. In the next step, genistein was encapsulated in MPS microstructure at different ratios, resulting in high loading capacity and efficiency (44.71% and 79.9%, respectively) at 1:1 weight ratio. Equilibrium adsorption isotherm of genistein was evaluated also by four different kinetics models including Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherms. The experimental data were found to be fitted well to the Langmuir model (R2 = 0.989). According to the electron microscopy and XRD analysis, the degree of genistein crystallinity lowered remarkably after the impregnation in to MPS, indicating improved solubility. In-vitro release profile of genistein from MPS in the simulated gastrointestinal buffer solutions (pH 1.2 and 6.8) demonstrated that incorporating genistein into the MPS enhanced the dissolution rate compared with genistein powder. Release kinetic data were fitted to the Higuchi model (R2 = 0.98), indicating diffusion-controlled release mechanism. Altogether, well-tuned MPS fabrication method can be utilized for an efficient encapsulation and dissolution enhancement of poorly soluble phytochemicals, such as genistein.

Development, characterisation and nasal deposition of melatonin-loaded pectin/hypromellose microspheres

In this study, we present the development of spray-dried pectin/hypromellose microspheres as efficient melatonin carrier for targeted nasal delivery. Different pectin to hypromellose weight ratios in the spray-dried feed were employed (i.e. 1:0, 3:1, 1:1 and 1:3) in order to optimise microsphere physicochemical properties influencing overall powder behaviour prior, during and upon nasal delivery. All microspheres assured complete melatonin entrapment and increased dissolution rate in relation to pure melatonin powder. Among all combinations tested, combining pectin with hypromellose at 1:3 wt ratio resulted in the microspheres with the highest potential for melatonin nasal delivery as they assured highest swelling ability and most prominent mucoadhesive properties. Studies on deposition profile revealed adequate turbinate and olfactory deposition of microsphere/lactose monohydrate powder blend administered nasally using MIAT® device, complementing findings relevant for their therapeutic potential. In conclusion, developed microspheres bear the potential to ensure prolonged melatonin retention at the nasal mucosa, improved bioavailability and advanced therapeutic outcome.

Loading paclitaxel into porous starch in the form of nanoparticles to improve its dissolution and bioavailability

In this work, paclitaxel was loaded into porous starch in the form of nanoparticles (PNPS), and the properties of PNPS were investigated by using raw paclitaxel and the system of paclitaxel directly loaded into porous starch (PPS) as control groups. According to the tested results, the drug loading (DL) and encapsulation efficiency (EE) of PNPS were 14.13%±0.27% and 73.92%±0.54%, higher than that of PPS (9.79%±0.31% and 71.17%±0.67%) respectively. Compared with raw paclitaxel and PPS, PNPS exhibited the more prominent dissolution rate and bioavailability, in which the bioavailability of PPS and PNPS were 2.94 and 5.42 times of that of raw paclitaxel respectively. In addition, the IC₅₀ values of raw paclitaxel, PPS and PNPS on Lewis Lung Carcinoma (LLC) cells were 17,703.41±15.76μM, 95.10±5.32μM and 85.68±7.38μM respectively. Furthermore, the residues of acetone in PPS and PNPS were less than the ICH limit for acetone in class III solvents. To summarize, the preparation of PNPS was a potential method to improve the dissolution and bioavailability of paclitaxel.