Preparation of the β-cyclodextrin-vitamin C (β-CD-Vc) inclusion complex under high hydrostatic pressure (HHP)

Collagen-β-cyclodextrin hydrogels for advanced wound dressings: super-swelling, antibacterial action, inflammation modulation, and controlled drug release

A key strategy in enhancing the efficacy of collagen-based hydrogels involves incorporating polysaccharides, which have shown great promise for wound healing. In this study, semi-interpenetrating polymeric network (semi-IPN) hydrogels comprised of collagen (Col) with the macrocyclic oligosaccharide β-cyclodextrin (β-CD) (20-80 wt.%) were synthesised. Fourier-transform infrared (FTIR) spectroscopy confirmed the successful fabrication of these Col/β-CD hydrogels, evidenced by the presence of characteristic absorption bands, including the urea bond band at ∼1740 cm-1, related with collagen crosslinking. Higher β-CD content was associated with increased crosslinking, higher swelling, and faster gelation. The β-CD content directly influenced the morphology and semi-crystallinity. All Col/β-CD hydrogels displayed superabsorbent properties, enhanced thermal stability, and exhibited slow degradation rates. Mechanical properties were significantly improved with contents higher than β-CD 40 wt.%. These hydrogels inhibited the growth of Escherichia coli bacteria and facilitated the controlled release of agents, such as malachite green, methylene blue, and ketorolac. The chemical composition of the Col/β-CD hydrogels did not induce cytotoxic effects on monocytes and fibroblast cells. Instead, they actively promoted cellular metabolic activity, encouraging cell growth and proliferation. Moreover, cell signalling modulation was observed, leading to changes in the expression of TNF-α and IL-10 cytokines. In summary, the results of this research indicate that these novel hydrogels possess multifunctional characteristics, including biocompatibility, super-swelling capacity, good thermal, hydrolytic, and enzymatic degradation resistance, antibacterial activity, inflammation modulation, and the ability to be used for controlled delivery of therapeutic agents, indicating high potential for application in advanced wound dressings.

Effect of hydrostatic pressure on the supramolecular assembly of surfactant-cyclodextrin inclusion complexes

The supramolecular assembly of simple colloids into complex, hierarchical structures arises from a delicate interplay of short-range directional and isotropic long-range forces. These assemblies are highly sensitive to environmental changes, such as temperature variations and the presence of specific molecules, making them promising candidates for nanomachine design. In this study, we investigate the effect of hydrostatic pressure, up to 1800 bar, on the supramolecular assemblies of cyclodextrin/surfactant complexes. Using small-angle neutron scattering, we demonstrate that while the overall structure of the supramolecular aggregates remains largely stable under pressure, the stiffness of the planar lattice formed by the inclusion complexes, the basic structural unit of the supramolecular assemblies, shows a fourfold increase between 250 and 1000 bar. These findings suggest that high-pressure studies can be exploited to better understand the mechanisms of supramolecular assembly processes, thereby aiding in the design of more robust and functional systems.

Improved triamcinolone acetonide-eluting contact lenses based on cyclodextrins and high hydrostatic pressure assisted complexation

Contact lenses (CLs) constitute an advantageous platform for the topical release of corticosteroids due to their prolonged contact with the eye. However, the lipophilic nature of corticosteroids hampers CLs' ability to release therapeutic amounts. Two approaches to improve loading and release of triamcinolone acetonide (TA) from poly(2-hydroxyethyl methacrylate)-based hydrogels were investigated: adding 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) to the monomers solution before polymerization (HEMA/i-CD) and an hydrogels' post-treatment with HP-β-CD (HEMA/p-CD). The effect of HP-β-CD and sterilization by high hydrostatic pressure (HHP) on the hydrogel properties (water content, oxygen and ion permeability, roughness, transmittance, and stiffness) was evaluated. The HEMA/i-CD hydrogels had stronger affinity for TA, sustaining its release for one day. HHP sterilization promoted the formation of cyclodextrin-TA complexes within the hydrogels, improving their drug-loading capacity »60 %. Cytotoxicity and irritability tests confirmed the safety of the therapeutic CLs. TA released from the hydrogels permeated through ocular tissues ex vivo and showed anti-inflammatory activity. Finally, a previously validated mathematical model was used to estimate the ability of the TA-loaded CLs to deliver therapeutic drug concentrations to the posterior part of the eye. Overall, HP-β-CD-containing CLs are promising candidates for the topical ocular application of TA as an alternative delivery system to intraocular injections.

The soybean lecithin-cyclodextrin-vitamin E complex nanoparticles stabilized Pickering emulsions for the delivery of β-carotene: Physicochemical properties and in vitro digestion

In this work, soybean lecithin (LC) was used to modify β-cyclodextrin (β-CD) with hydrophobic fat chains to become amphiphilic (LC-CD), and vitamin E (VE) was encapsulated in former modified β-CD complexes (LC-CD-VE), the new Pickering emulsions stabilized by LC-CD-VE and LC-CD complexes for the delivery of β-carotene (BC) were created. The surface tension, contact angle, zeta potential, and particle size were used to assess the changes in complexes nanoparticles at various pH values. Furthermore, LC-CD-VE has more promise as Pickering emulsion stabilizer than LC-CD because of the smaller particle size (271.11 nm), proper contact angle (58.02°), and lower surface tension (42.49 mN/m). The interactions between β-cyclodextrin, soybean lecithin, and vitamin E were confirmed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and thermogravimetric analysis (TGA). The durability of Pickering emulsions was examined at various volume fractions of the oil phase and concentrations of nanoparticles. Compared to the emulsion stabilized by LC-CD, the one stabilized by LC-CD-VE showed superior storage stability. Moreover, for the delivery of BC, Pickering emulsions stabilized by LC-CD and LC-CD-VE can outperform bulk oil and Tween 80 stabilized emulsions in terms of UV light stability, storage stability, and bioaccessibility. This work could offer fresh perspectives on stabilizer alternatives for Pickering emulsion delivery systems.

Governing the aggregation of type I collagen mediated through β-cyclodextrin

The effect of carbohydrates on collagen self-assembly behavior has been widely investigated because of their regulation on collagen fibrogenesis in vivo. In this paper, β-cyclodextrin (β-CD) was selected as an external disturbance to explore its intrinsic regulating mechanism on collagen self-assembly. The results of fibrogenesis kinetics indicated that β-CD had a bilateral regulation on collagen self-aggregation process, which was closely related to the content of β-CD: collagen protofibrils with low β-CD content were less aggregated compared to collagen protofibrils with high β-CD content. However, typical periodic stripes of ~67 nm on collagen fibrils were observed from transmission electron microscope (TEM), indicating that β-CD did not disturb the lateral arrangement of collagen molecules to form a 1/4 staggered structure. Correspondingly, the degree of aggregation of collagen self-assembled fibrils was closely correlated with the addition of β-CD content, as confirmed by field emission scanning electron microscopy (FESEM) and atomic force microscope (AFM). In addition, collagen/β-CD fibrillar hydrogel had good thermal stability and cytocompatibility. These results provide a better understanding of how to construct a structurally reliable collagen/β-CD fibrillar hydrogel as a biomedical material in a β-CD-regulated environment.

Preparation and Spectroscopic Characterization of Ternary Inclusion Complexes of Ascorbyl Palmitate and Urea with γ-Cyclodextrin

A three-component inclusion complex of ascorbyl palmitate (ASCP), urea (UR), and γ-cyclodextrin (γCD) with a molar ratio of 1/12 has been prepared for the first time using the evaporation method (EVP method) and the grinding and mixing method (GM method). Also, we investigated changes in the physicochemical properties of the three-component complexes. The powder X-ray diffraction (PXRD) measurements showed ASCP, UR, and γCD characteristic peaks in the physical mixture (PM) (AU (ASCP/UR = 1/12)/γCD = 1/2). In GM (AU (ASCP/UR = 1/12)/γCD = 1/1), new diffraction peaks were observed around 2θ = 7.5° and 16.6°, while characteristic peaks derived from EVP (ASCP/UR = 1/12) were observed at 2θ = 23.4° and 24.9°. On the other hand, new diffraction peaks at 2θ = 7.4° and 16.6° were observed in GM (1/2). In the differential scanning calorimeter (DSC) measurement, an endothermic peak at around 83 °C was observed in the GM (1/1) sample, which is thought to originate from the phase transition of urea from the hexagonal to the tetragonal form. An endothermic peak around 113.9 °C was also observed for EVP (ASCP/UR = 1/12). However, no characteristic phase transition-derived peak or EVP (ASCP/UR = 1/12)-derived endothermic peak was observed in GM (1/2). Near infrared (NIR) spectroscopy of GM (1/2) showed no shift in the peak derived from the CH group of ASCP. The peaks derived from the NH group of UR shifted to the high and low wavenumber sides at 5032 cm−1 and 5108 cm−1 in EVP (ASCP/UR = 1/12). The peak derived from the OH group of γCD shifted, and the peak derived from the OH group of ASCP broadened at GM (1/2). These results suggest that AU (ASCP/UR = 1/12)/γCD prepared by the mixed grinding method formed inclusion complexes at the molar ratio (1/2).

Fabrication of core-shell type poly(NIPAm)-encapsulated citral and its application on bamboo as an anti-molding coating

Bamboo is a widely used renewable and degradable biomass material; however, its sustainable utilisation is hindered by its susceptibility to mold. The current bamboo anti-mold technology is mainly based on organic chemical agents; these agents can easily induce mold resistance in bamboo with long-term use, and can even adversely affect human health. In the present study, the poly(N-isopropyl acrylamide) (PNIPAm)/citral nanohydrogel was prepared by encapsulating the natural antibiotic citral in PNIPAm for the anti-mold treatment of bamboo. The results revealed that this nanohydrogel exhibited a core-shell system with citral as the 'core' and PNIPAm as the 'shell', an average hydrodynamic diameter of 88.1 nm, and a low critical solution temperature (LCST) of 35.4 °C. After the high-pressure impregnation with the nanohydrogel, the bamboo strips showed excellent control effects toward common bamboo molds. Therefore, the nanohydrogel demonstrated high efficiency and it may become an ideal alternative to organic chemical anti-mold agents, thus showcasing its significant potential in the field of mold prevention for bamboo.

Topological cyclodextrin nanoparticles as crosslinkers for self-healing tough hydrogels as strain sensors

Hydrogels have been widely used for various applications, and thus addressing the challenges associated with the design of sustainable hydrogels has become an important issue. However, little attention has been devoted toward the design of crosslinkers which are often toxic, lack self-healing capabilities, and derived from petrochemicals. Herein, novel cyclodextrin topological nanoparticles (TNPs) have been constructed. These TNPs were found to possess crosslinking capabilities and the corresponding TNPs-crosslinked hydrogels showed excellent mechanical performances with a high stretchability of 1860 % and stress of 180 kPa and good anti-fatigue abilities. These hydrogels could be readily recycled and used for modular assembly and disassembly in various shapes and could serve as flexible strain sensors to monitor human activities with a sensing range of 0-1800 %, controllable sensitivity, and good fatigue resistance. These topological nanoparticles can inspire the design of novel physical crosslinkers for novel flexible strain sensors, tough and self-healing hydrogels, and soft robotics.

Role of Lipid Metabolism and Signaling in Mammalian Oocyte Maturation, Quality, and Acquisition of Competence

It has been found that the quality of oocytes from obese women has been compromised and subsequent embryos displayed arrested development. The compromised quality may be either due to the poor or rich metabolic conditions such as imbalance or excession of lipids during oocyte development. Generally, lipids are mainly stored in the form of lipid droplets and are an important source of energy metabolism. Similarly, lipids are also essential signaling molecules involved in various biological cascades of oocyte maturation, growth and oocyte competence acquisition. To understand the role of lipids in controlling the oocyte development, we have comprehensively and concisely reviewed the literature and described the role of lipid metabolism in oocyte quality and maturation. Moreover, we have also presented a simplified model of fatty acid metabolism along with its implication on determining the oocyte quality and cryopreservation for fertilization.

Highly branched corn starch: Preparation, encapsulation, and release of ascorbic acid

The aim of this study was to prepare a supporting carrier, namely highly branched corn starch (HBCS), and to investigate its encapsulation property with ascorbic acid (AA). High amylose corn starch was converted into HBCS via dual enzymatic modification by successively using α-amylase and glycogen branching enzyme. The results showed that the ratio of α-1, 6 linkage of HBCS increased by 1.93%, and a short-to-medium chain length distribution with a compact branched conformation was formed, which suggested HBCS could be a potential highly branched carrier. The HBCS-AA inclusion complex was formed as confirmed by differential scanning calorimetry. The release of AA conformed to the pseudo-Fickian diffusion mechanism and followed the first-order kinetics. Meanwhile, the photostability and thermostability of the embedded AA were moderately enhanced. These findings suggest that HBCS provides new insights into the preparation of wall materials and can be potentially used to deliver AA into food systems.

Effects of α-, β- and maltosyl-β-cyclodextrins use on the glucoraphanin-sulforaphane system of broccoli juice

Cyclodextrins (CDs) are macromolecules with several industrial applications, being particularly used in the food industry as health-promoting compounds protection agents, as flavour stabilizers, or to eliminate undesired tastes and browning reactions, among others. This study shows the effects of α- (10, 30 and 40 mmol L^-1 ), β- (3, 6 and 10 mmol L^-1 ) and maltosyl-β-CDs (30, 60 and 90 mmol L^-1 ) use on the health-promoting glucoraphanin-sulforaphane system of a broccoli juice up to 24 h at 22 °C. Maltosyl-β-CD (90 mmol L^-1 ) highly retained glucoraphanin content after 24 h at 22 °C, showing better effectiveness than β-CD (10 mmol L^-1 ). Sulforaphane was efficiently encapsulated with β-CD at just 3 mmol L^-1 , and the sulforaphane formed was stable during 3 h at 22 °C. On the other hand, 40 mmol L^-1 α-CD retained a high glucoraphanin content in broccoli juice. In contrast, glucoraphanin levels in juice without CDs decreased by 71% after 24 h. Consequently, CDs addition may potentially preserve glucoraphanin in this broccoli juice during industrial processing with the possibility to be later transformed by endogenous myrosinase after ingestion to the health-promoting sulforaphane. © 2018 Society of Chemical Industry.

Ascorbic acid-cyclodextrin complex alters the expression of genes associated with lipid metabolism in bovine in vitro produced embryos

Ascorbic acid (AC) used as antioxidant in embryo culture is very sensitive and degrades unavoidably in aqueous solution. Methyl-β-cyclodextrin (CD) improved the stability of AC in solution to elevated temperature, light, humidity and oxidation. The aim of this study was to evaluate the effect of the complex AC-CD during in vitro maturation (IVM) or in vitro culture (IVC) on oocyte developmental competence and subsequent embryo development and quality. AC-CD (100 µM) was added to IVM media, and maturation level and embryo development were examined. Matured oocytes, their cumulus cells and produced blastocysts were snap-frozen for gene expression analysis by RT-qPCR. Besides, in vitro-produced zygotes were cultured with 100 µM of AC-CD and blastocysts were as well snap-frozen for gene expression analysis. A group without AC-CD (control^- ) and other with CD (control⁺ ) were included. No differences were found on maturation, cleavage or blastocyst rates. However, in matured oocytes, AC-CD downregulated BAX, GPX1 and BMP15. In cumulus cells, AC-CD downregulated BAX/BCL2 and GSTA4 while upregulated BCL2 and CYP51A1. The expression of SL2A1, FADS1, PNPLA and MTORC1 was downregulated in blastocysts derived from oocytes matured with AC-CD, while in blastocysts derived from zygote cultured with AC-CD, CYP51A1 and IGF2R were downregulated and PNPLA2 was upregulated. In conclusion, AC-CD in both IVM and IVC media may reduce accumulated fat by increasing lipolysis and suppressing lipogenesis in blastocysts derived from both oocytes and zygotes cultured with AC-CD, suggesting that CD improves the quality of embryos and bioavailability of AC during IVM and IVC.

A novel multi-tiered experimental approach unfolding the mechanisms behind cyclodextrin-vitamin inclusion complexes for enhanced vitamin solubility and stability

This study was conducted to provide a mechanistic account for understanding the synthesis, characterization and solubility phenomena of vitamin complexes with cyclodextrins (CD) for enhanced solubility and stability employing experimental and in silico molecular modeling strategies. New geometric, molecular and energetic analyses were pursued to explicate experimentally derived cholecalciferol complexes. Various CD molecules (α-, β-, γ-, and hydroxypropyl β-) were complexed with three vitamins: cholecalciferol, ascorbic acid and α-tocopherol. The Inclusion Efficiency (IE%) was computed for each CD-vitamin complex. The highest IE% achieved for a cholecalciferol complex was for 'βCDD₃-8', after utilizing a unique CD:cholecalciferol molar synthesis ratio of 2.5:1, never before reported as successful. 2HPβCD-cholecalciferol, γCD-cholecalciferol and α-tocopherol inclusion complexes (IC's) reached maximal IE% with a CD:vitamin molar ratio of 5:1. The results demonstrate that IE%, thermal stability, concentration, carrier solubility, molecular mechanics and intended release profile are key factors to consider when synthesizing vitamin-CD complexes. Phase-solubility data provided insights into the design of formulations with IC's that may provide analogous oral vitamin release profiles even when hydrophobic and hydrophilic vitamins are co-incorporated. Static lattice atomistic simulations were able to validate experimentally derived cholecalciferol IE phenomena and are invaluable parameters when approaching formulation strategies using CD's for improved solubility and efficacy of vitamins.

Recent Advances in Food Processing Using High Hydrostatic Pressure Technology

High hydrostatic pressure is an emerging non-thermal technology that can achieve the same standards of food safety as those of heat pasteurization and meet consumer requirements for fresher tasting, minimally processed foods. Applying high-pressure processing can inactivate pathogenic and spoilage microorganisms and enzymes, as well as modify structures with little or no effects on the nutritional and sensory quality of foods. The U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) have approved the use of high-pressure processing (HPP), which is a reliable technological alternative to conventional heat pasteurization in food-processing procedures. This paper presents the current applications of HPP in processing fruits, vegetables, meats, seafood, dairy, and egg products; such applications include the combination of pressure and biopreservation to generate specific characteristics in certain products. In addition, this paper describes recent findings on the microbiological, chemical, and molecular aspects of HPP technology used in commercial and research applications.

Study to explore the mechanism to form inclusion complexes of β-cyclodextrin with vitamin molecules

Host–guest inclusion complexes of β-cyclodextrin with two vitamins viz., nicotinic acid and ascorbic acid in aqueous medium have been explored by reliable spectroscopic, physicochemical and calorimetric methods as stabilizer, carrier and regulatory releaser of the guest molecules. Job’s plots have been drawn by UV-visible spectroscopy to confirm the 1:1 stoichiometry of the host-guest assembly. Stereo-chemical nature of the inclusion complexes has been explained by 2D NMR spectroscopy. Surface tension and conductivity studies further support the inclusion process. Association constants for the vitamin-β-CD inclusion complexes have been calculated by UV-visible spectroscopy using both Benesi–Hildebrand method and non-linear programme, while the thermodynamic parameters have been estimated with the help of van’t Hoff equation. Isothermal titration calorimetric studies have been performed to determine the stoichiometry, association constant and thermodynamic parameters with high accuracy. The outcomes reveal that there is a drop in ΔS^o, which is overcome by higher negative value of ΔH^o, making the overall inclusion process thermodynamically favorable. The association constant is found to be higher for ascorbic acid than that for nicotinic acid, which has been explained on the basis of their molecular structures.

A novel bile salts-lipase polymeric film-infused minitablet system for enhanced oral delivery of cholecalciferol

Few researchers have investigated the use of multiple physiological enhancers combined with synthetic carriers to augment delivery of nutraceuticals. The current work describes the development of an oral delivery system termed a bioactive association platform (BAP) capable of delivering nutraceutical actives from a formulation framework specifically for enhancing the in vitro and in vivo performance of model vitamin, cholecalciferol (Vitamin D₃). Synthesis of a novel triple vitamin minitablet and an optimized bile salt/lipase alginate-glycerin film provided unique oral components for inclusion in a BAP capsule. Component validation and physicochemical characterizations included comparative ex vivo permeability, chemical structure mapping, thermodynamic analysis and magnetic resonance imaging. In vitro dissolution studies of the BAP produced an area under the dissolution curve (AUC) for cholecalciferol release that was 28% greater than a conventional comparator product. A total of 84.01% of cholecalciferol was released from the BAP within 3 h versus only 59% from a comparator. Ex vivo permeation studies revealed superior cholecalciferol membrane diffusion from the triple vitamin minitablet BAP component. In vivo performance showed a greater mean change from baseline cholecalciferol to peak plasma levels (C_max) from the BAP compared to the comparator (55.66 versus 46.05 ng/mL). Cholecalciferol bioavailability was improved in vivo with an AUC_0-inf from the BAP that was 3.2× greater than the conventional product. The BAP was also superior at improving and maintaining serum levels of the main metabolite, 25-hydroxyvitamin D₃, compared to the conventional system. In vitro and in vivo results thus confirmed improvements in cholecalciferol dissolution, membrane permeability and plasma drug levels. The study results position the BAP as an ideal oral vehicle for enhanced delivery of cholecalciferol.

Preparation and characterization of inclusion complex of benzyl isothiocyanate extracted from papaya seed with β-cyclodextrin

The inclusion complex of benzyl isothiocyanate (BITC), extracted from papaya seed with β-cyclodextrin (β-CD), was prepared. Different analytical techniques, such as Fourier transform infrared spectroscopy, thermal analysis, X-ray diffractometry, particle size distribution analysis and (1)H Nuclear magnetic resonance analysis, were used to investigate the characterization of the inclusion complex (BITC-β-CD). All these approaches indicated that the inclusion complex was capable of being formed. The inclusion complex exhibited different spectroscopic and thermodynamic features and properties from BITC, and we deduced the possible inclusion modes for BITC-β-CD. The calculated apparent stability constant of the BITC-β-CD was 600.8l/mol, and the aqueous solubility of BITC was indistinctively improved by phase solubility studies. The results illustrated that β-CD was a proper excipient for increasing the stability and controlled release of BITC. Thus, β-CD complexation technology would be a promising approach, in expanding the application of BITC as a food antibacterial agent.

Preparation, characterization, and in vitro release of carboxymethyl starch/β-cyclodextrin microgel–ascorbic acid inclusion complexes

CMS/β-CD microgels prevented the early release of ascorbic acid in the stomach and target delivery of them to the intestine due to the ionization of carboxylic groups.

Preparation, characterization, and thermal stability of β-cyclodextrin/soybean lecithin inclusion complex

β-Cyclodextrin (β-CD), which is widely used to increase the stability, solubility, and bioavailability of guests, can form host-guest inclusion complexes with a wide variety of organic molecules. In this study the β-CD/soybean lecithin inclusion complex was prepared. The effect of reaction parameters such as reaction temperature, reaction time and the molar ratio of β-CD/soybean lecithin on inclusion ratio were studied. The inclusion ratio of the product prepared under the optimal conditions of β-CD/soybean lecithin molar ratio 2:1, reaction temperature 60°C reaction time 2h was 40.2%. The results of UV-vis, DSC, XRD and FT-IR spectrum indicated the formation of inclusion complex. The thermal stability experiment indicated that the thermal stability of soybean lecithin in inclusion complex was significantly improved compared with free soybean lecithin.