Hydrophilic Outer Surface Research Articles

Upcycling of industrial pea starch by rapid spray nanoprecipitation to develop plant-derived oil encapsulated starch nanoparticles for potential agricultural applications

Starch is one of the natural encapsulant materials widely used in food, pharmaceutical and cosmetic industries. Starch with high amylose content (above 40 %, w/w) is prone to form single helices V-type allomorph with a hydrophilic outer surface and a hydrophobic inner cavity making them suitable for encapsulation of hydrophobic compounds such as essential oils, fatty acids, and vitamins. Pea starch obtained from pea protein processing industries have a high amylose content (40 %, w/w) rendering them unsuitable for direct food applications as ingredients. Therefore, in this study, an in-house spraying procedure was used to synthesize nanoparticles using pea starch, to encapsulate neem oil, a natural antimicrobial compound obtained from neem plant (Azadirachta indica) seed. The synthesis of the oil-encapsulated starch nanoparticles (OESNP) was optimized using a Box-Behnken experimental design to study the influence of the processing parameters such as the initial starch concentration, homogenization speed, duration of homogenization, sample injection rate, and quantity of antisolvent (ethanol). The optimized sample showed an 80–90 % encapsulation efficiency and particle size of <500 nm. The spherical OESNPs also demonstrated sustained release of the oil compared to free oil when dispersed in water. X-ray diffraction analysis revealed the coexistence of C-type and V-type polymorphs in the loaded and unloaded nanoparticles. It is concluded that the synthesized OESNPs with controlled release hold the potential to utilize industrial pea starch waste for the delivery of natural pesticides in agriculture.

Reusable Cyclodextrin-Mediated Electrochemical Sensor in Automated Flow Cell for Cortisol Detection

Our focus is on using beta cyclodextrin (βCD) to electrochemically detect cortisol; cortisol is a hydrophobic molecule that is a vital hormone, and cortisol is involved in the immune system, metabolism, heart health, and overall body balance. Cyclodextrins, characterized by a hydrophobic inner cavity and a hydrophilic outer surface, emerge as promising molecular receptors for detecting hydrophobic molecules. Notably, βCD and cortisol can form host/guest inclusion complexes. Building on our success in detecting cortisol with βCD in previous static cell experiments [1], herein we introduce innovations to further improve our methodology by employing an automated flow cell system. The transition to automation offers advantages such as repeated runs for obtaining more reproducible data and the elimination of human interactions and considerations, leading to an increased number of experiments. Our efforts, including the utilization of a ten-way multi-position valve and a pump for solution transfer, were crucial for enhancing the accuracy, stability, and reproducibility of cyclodextrin-mediated biosensors in automated flow cell systems. The automation process did encounter challenges, particularly with pump control, necessitating manual pauses before electrochemical measurements. Additionally, issues related to bubbles arose, prompting the search for the optimal flow rate and the utilization of a degasser. The ultimate goal is to optimize sensor stability, sensitivity, and reproducibility, contributing to the advancement of cortisol detection with the automated cyclodextrin-mediated biosensors.Research supported by New Hampshire- INBRE through an Institutional Development Award (IDeA), P20GM103506, from the National Institute of General Medical Sciences of the NIH. Support was also provided by a National Science Foundation EPSCoR award (#2119237), BIO-SENS.[1] Z. Panahi, T. Ren, and J. M. Halpern, “Nanostructured Cyclodextrin-Mediated Surface for Capacitive Determination of Cortisol in Multiple Biofluids,” ACS Appl. Mater. Interfaces, vol. 14, no. 37, pp. 42374–42387, Sep. 2022, doi: 10.1021/acsami.2c07701.

Development and Evaluation of Curcumin-based Transferosomal Gel for Wound Healing

Background: Recently, transferosomes have been discovered to have the potential for transdermal delivery. Curcumin is a bioactive molecule with anti-inflammatory and antioxidant properties, but it has low water solubility and poor skin absorption. The biological response to damage caused by diverse stimuli is known as the inflammatory process. Cyclodextrins are cyclic (-1, 4)-linked oligosaccharides of -D-glucopyranose with a hydrophilic outer surface and a hydrophobic center cavity. Aim: The aim of the study was to develop a curcumin-loaded transferosomal gel to improve the wound healing process. The study has focused on advancing the area of traditional medicine in the field of pharmaceutics by using curcumin in the form of transferosomes to enhance wound healing. Method: Firstly, curcumin was used to synthesize the transferosomes. Secondly, the transferosomes were converted into a transferosomal gel as an alternative for wound healing. Characterization and in vivo investigation were carried out on female Swiss mice. Results: Unpaired Student’s t-test was used to determine the statistical significance at p &lt; 0.5 using UV exposure schedules. All values have been expressed as mean ± SEM calculated by ANOVA with a significant difference among means at P &lt; 0.05. Conclusion: The study has indicated curcumin to be successfully entrapped in transferosomes in order to formulate the gel with powerful wound healing properties.

ESI-IM-MS characterization of cyclodextrin complexes and their chemically cross-linked alpha (α-), beta (β-) and gamma (γ-) cyclodextrin particles as promising drug delivery materials with improved bioavailability.

Cyclodextrins (CDs) are natural cyclic oligosaccharides with a relatively hydrophobic cavity and a hydrophilic outer surface. In this study, alpha (α-), beta (β-) and gamma (γ-) CD particles were prepared by directly using α-, β-, and γ-CDs as monomeric units and divinyl sulfone (DVS) as a crosslinker in a single-step via reverse micelle microemulsion crosslinking technique. Particles of p(α-CD), p(β-CD), and p(γ-CD) were perfectly spherical in sub- 10µm size ranges. The prepared p(CD) particles at 1.0mg/mL concentrations were found biocompatible with >95 % cell viability against L929 fibroblasts. Furthermore, p(α-CD) and p(β-CD) particles were found non-hemolytic with <2 % hemolysis ratios, whereas p(γ-CD) particles were found to be slightly hemolytic with its 2.1±0.4 % hemolysis ratio at 1.0mg/mL concentration. Furthermore, a toxic compound, Bisphenol A (BPA) and a highly antioxidant polyphenol, curcumin (CUR) complexation with α-, β-, and γ-CD molecules was investigated via Electrospray-Ion Mobility-Mass Spectrometry (ESI-IM-MS) and tandem mass spectrometry (MS/MS) analysis. It was determined that the most stable noncovalent complex was in the case of β-CD, but the complex stoichiometry was changed by the hydrophobic nature of the guest molecules. In addition, BPA and CUR were separately loaded into prepared p(CD) particles as active agents. The drug loading and release studies showed that p(CD) particles possess governable loading and releasing profiles.

Cyclodextrins and Their Derivatives as Drug Stability Modifiers.

Cyclodextrins (CDs) are cyclic oligosaccharides that contain a relatively hydrophobic central cavity and a hydrophilic outer surface. They are widely used to form non-covalent inclusion complexes with many substances. Although such inclusion complexes typically exhibit higher aqueous solubility and chemical stability than pure drugs, it has been shown that CDs can promote the degradation of some drugs. This property of stabilizing certain drugs while destabilizing others can be explained by the type of CD used and the structure of the inclusion complex formed. In addition, the ability to form complexes of CDs can be improved through the addition of suitable auxiliary substances, forming multicomponent complexes. Therefore, it is important to evaluate the effect that binary and multicomponent complexes have on the chemical and physical stability of complexed drugs. The objective of this review is to summarize the studies on the stabilizing and destabilizing effects of complexes with CDs on drugs that exhibit stability problems.

Application of Cyclodextrin for Cancer Immunotherapy.

Tumor immunotherapy, compared with other treatment strategies, has the notable advantage of a long-term therapeutic effect for preventing metastasis and the recurrence of tumors, thus holding great potential for the future of advanced tumor therapy. However, due to the poor water solubility of immune modulators and immune escape properties of tumor cells, the treatment efficiency of immunotherapy is usually significantly reduced. Cyclodextrin (CD) has been repeatedly highlighted to be probably one of the most investigated building units for cancer therapy due to its elegant integration of an internal hydrophobic hollow cavity and an external hydrophilic outer surface. The application of CD for immunotherapy provides new opportunities for overcoming the aforementioned obstacles. However, there are few published reviews, to our knowledge, summarizing the use of CD for cancer immunotherapy. For this purpose, this paper provides a comprehensive summary on the application of CD for immunotherapy with an emphasis on the role, function, and reported strategies of CD in mediating immunotherapy. This review summarizes the research progress made in using CD for tumor immunotherapy, which will facilitate the generation of various CD-based immunotherapeutic delivery systems with superior anticancer efficacy.

Aqueous-phase hydrogenation of α-pinene to cis-pinane using an amphiphilic Ni-based catalyst

Alpha-pinene is an important forest chemical resource, and the cis-pinane obtained by its hydrogenation reaction is used in spices, medicine, and other industries. A hollow nanospheric material with amphiphilic properties in a two-sided structure was prepared, with a nitrogen-doped carbon layer towards the inside and mesoporous silica in the outer layer of the nanospheres. The amphiphilic catalyst with non-precious nickel as the active component was synthesized by loading nickel onto the nanospheres using a simple impregnation method and applied to the aqueous phase hydrogenation reaction of α-pinene. The mesoporous structure of the catalyst shortened the mass transfer distance and thus reduced the mass transfer resistance. The nitrogen atoms doped in the carbon matrix provided anchor points for stabilizing the metal nanoparticles; the hydrophilic outer surface and hydrophobic hollow cavity enabled the catalyst to be well dispersed in water while still enriching the organic matter in aqueous solution. The effect of various reaction conditions on the catalytic reaction was investigated. The catalysts showed excellent activity and good stability, suggesting a new green and efficient method for more effective exploitation of biomass pine resin resources, and providing a reference for expanding the application of non-precious metal catalysts.

Cyclodextrins: Only Pharmaceutical Excipients or Full-Fledged Drug Candidates?

Cyclodextrins, representing a versatile family of cyclic oligosaccharides, have extensive pharmaceutical applications due to their unique truncated cone-shaped structure with a hydrophilic outer surface and a hydrophobic cavity, which enables them to form non-covalent host-guest inclusion complexes in pharmaceutical formulations to enhance the solubility, stability and bioavailability of numerous drug molecules. As a result, cyclodextrins are mostly considered as inert carriers during their medical application, while their ability to interact not only with small molecules but also with lipids and proteins is largely neglected. By forming inclusion complexes with cholesterol, cyclodextrins deplete cholesterol from cellular membranes and thereby influence protein function indirectly through alterations in biophysical properties and lateral heterogeneity of bilayers. In this review, we summarize the general chemical principles of direct cyclodextrin-protein interactions and highlight, through relevant examples, how these interactions can modify protein functions in vivo, which, despite their huge potential, have been completely unexploited in therapy so far. Finally, we give a brief overview of disorders such as Niemann-Pick type C disease, atherosclerosis, Alzheimer's and Parkinson's disease, in which cyclodextrins already have or could have the potential to be active therapeutic agents due to their cholesterol-complexing or direct protein-targeting properties.

Amphiphilic hypercrosslinked β-cyclodextrin polymers with rigid networks for efficient acteoside separation

In this study, a series of amphiphilic hypercrosslinked β-cyclodextrin polymers (AHβ-CDPs) were synthesized by the hypercrosslinked strategy for acteoside (ACT) separation. Amphiphilic β-cyclodextrin (β-CD) had rigid ring structures, which constructed the rigid networks of AHβ-CDPs. AHβ-CDPs with rigid networks improved adsorption performance for two reasons. On one hand, the hydrophilic ACT was preferentially adsorbed on the hydrophilic outer surface of β-CD, and the hydrophobic molecules were encapsulated in the hydrophobic cavity, improving adsorption selectivity. On the other hand, the constructed rigid networks of AHβ-CDPs with affinity groups provided large specific surface area (1281.16 m2/g) and abundant pore structure, increasing additional transport pathways and affinity sites for enhancing adsorption capacity. The experimental results showed the as-prepared AHβ-CDPs-4 had the highest adsorption capacity of 288.36 ± 2.12 mg/g and the selectivity of 4.36 ± 0.11. Therefore, amphiphilic hypercrosslinked adsorbents with rigid networks had potential application for bioactive components separation from natural products.

A Dual-Parameter Optical Fiber SPR Sensor for Simultaneous Measurement of Glucose and Cholesterol Concentrations

A surface plasmon resonance (SPR) dual-parameter sensor is designed and fabricated. It was electroless plated with silver on the surface of the core of the plastic-clad optical fiber and a gold film was plated near the end face side to produce the double SPR resonance valleys. 4-mercaptophenylboronic acid (4-MPBA) and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -cyclodextrin ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -CD) were coated separately on the surface of the silver and gold films. 4-MPBA can selectively recognize the structures of cis-vicinal diols, and thus can capture glucose that contains such structures. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -CD is a class of cyclic oligosaccharides whose unique hydrophilic outer surface and lipophilic central cavity help facilitate the formation of inclusion complexes with cholesterol through multiple interactions. The sensor can detect 0–4 mM glucose and 0–500 nM cholesterol, and it has a linear response in the concentration range of 0–0.1 mM glucose and 0–15 nM cholesterol. The sensitivity of glucose and cholesterol concentration of the sensor is 89.6 and 0.994 nm/nM, respectively. The detection limits for quantifying glucose and cholesterol are <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.12~\mu \text{M}$ </tex-math></inline-formula> and 0.1 nM, respectively. The experimental results also show that the sensor has good selectivity and stability. The proposed technique can be further applied in medicine, environment, and biology monitoring.

Lipid-Drug Conjugates and Nanoparticles for the Cutaneous Delivery of Cannabidiol.

Lipid nanoparticles are currently used to deliver drugs to specific sites in the body, known as targeted therapy. Conjugates of lipids and drugs to produce drug-enriched phospholipid micelles have been proposed to increase the lipophilic character of drugs to overcome biological barriers. However, their applicability at the topical level is still minimal. Phospholipid micelles are amphiphilic colloidal systems of nanometric dimensions, composed of a lipophilic nucleus and a hydrophilic outer surface. They are currently used successfully as pharmaceutical vehicles for poorly water-soluble drugs. These micelles have high in vitro and in vivo stability and high biocompatibility. This review discusses the use of lipid-drug conjugates as biocompatible carriers for cutaneous application. This work provides a metadata analysis of publications concerning the conjugation of cannabidiol with lipids as a suitable approach and as a new delivery system for this drug.

Beta-Cyclodextrin As An Excipient In Drug Formulation

After its discovery nearly 30 years ago, (2-Hydroxy –propyl) Beta –Cyclodextrin, a highly soluble derivative of Beta –Cyclodextrin, has been an authorized excipients of drug formulation in both the US and European pharmacopoeia. It is recommended for use in oral and parenteral formulations as a solubilizer and stabilizer. The majority of medications taken by mouth have low aqueous solubility and dissolution rates. Beta-Cyclodextrin that has been chemically modified Dynamic complex formation used to enchance the Low aqueous solubility, slow dissolution rate, and reduced drug stability. Cyclodextrin form inclusion complexes with appropriately sized guest molecules to improve aqueous solubility, physical chemical stability, and bioavailability of drugs. Cyclodextrin is a group of compounds made up of glucose monomers arranged in a donut form. They are non-reducing, crystalline cyclic oligosaccrides with a truncated core that produces a hydrophilic outer surface. Cyclodextrin and its derivatives have become common modalities for increasing oral bio availability and absorption rate as a result of these effects. Cyclodextrin has been positioned as an effective facilitating and usable excipients. This article discusses the widespread use of Cyclodextrin as excipients in drug formulations as well as recent Cyclodextrin developments.&#x0D;

Polyether-Cyclodextrin Modified Surfaces for Sensing of Hydrophobic Molecules

Electrochemical Impedance Spectroscopy (EIS) is a broadly used technique to study various surface phenomena in soft matter. For development of cyclodextrin based biosensors, we employ faradaic EIS in the presence of ferri/ferrocyanide to characterize polymer modified surfaces, investigate polymer conformational changes, and evaluate reusability and stability of the biosensors (1).Cyclodextrins consisting of six (αCD), seven (βCD), or eight (γCD) glucose units are composed of a hydrophobic inner cavity and a hydrophilic outer surface. Hydrophobic inner cavity of cyclodextrins have made them promising candidates as molecular receptors for detection of hydrophobic molecules such as trans-resveratrol and cortisol. Health-benefiting effects of trans-resveratrol have been reported in various studies, including those reviewed by Prof. Denis Petters (2). Development of a reusable sensor platform for monitoring hydrophobic species could aid in pharmacokinetics studies and metabolite profiling of trans-resveratrol.To make a reusable resveratrol biosensor, we first modify the gold electrode surface with polyethylene glycol (PEG). The PEG modified surface is then complexed with αCD. The αCD molecules are released from the surface in the presence of trans-resveratrol, which causes PEG molecules to flatten into a bent-over configuration which decreases the electron transfer rate. The surface can be regenerated by αCD reloading, which results in PEG chains forming microcrystalline channel-type domains and increases the electron transfer rate. With the assistance of EIS, we can confirm the charge transfer resistance increase by αCD release and charge transfer resistance increase by αCD reload. Moreover, Nyquist plots of consecutive reloading and release of αCD indicate that the PEG-αCD surface can successfully be regenerated for at least three time.Herein, we will detail our PEG-αCD surface for the detection of resveratrol and our PPG-βCD surface for the detection of cortisol. These surfaces behave similarly in their surface configuration state and EIS analysis. Further investigation in the reusability indicates the modified gold surfaces can be reused for three times but fail when regenerated for more than four times. We assume this limitation is imposed by low stability of gold–thiol bonds, and we will discuss our progress to overcome this issue in studying the formation of more stable covalent bonds through aryl diazonium salts. Acknowledgments: This work was supported by NIH P20 GM113131. References Panahi Z, Merrill MA, Halpern JM. Reusable Cyclodextrin-Based Electrochemical Platform for Detection of trans-Resveratrol. ACS Appl Polym Mater. 2020 Nov 13; 2(11):5086–93. Available from: https://dx.doi.org/10.1021/acsapm.0c00866Rauf A, Imran M, Sulera HAR, Ahmad B, Peters DG, Mubarak MS. A comprehensive review of the health perspectives of resveratrol. Vol. 8, Food and Function. Royal Society of Chemistry; 2017. p. 4284–305. Available from: https://pubs.rsc.org/en/content/articlehtml/2017/fo/c7fo01300k

Design of Cyclodextrin-Based Functional Systems for Biomedical Applications.

Cyclodextrins (CDs) are a family of α-1,4-linked cyclic oligosaccharides that possess a hydrophobic cavity and a hydrophilic outer surface with abundant hydroxyl groups. This unique structural characteristic allows CDs to form inclusion complexes with various guest molecules and to functionalize with different substituents for the construction of novel sophisticated systems, ranging from derivatives to polymers, metal-organic frameworks, hydrogels, and other supramolecular assemblies. The excellent biocompatibility, selective recognition ability, and unique bioactive properties also make these CD-based functional systems especially attractive for biomedical applications. In this review, we highlight the characteristics and advantages of CDs as a starting point to design different functional materials and summarize the recent advances in the use of these materials for bioseparation, enzymatic catalysis, biochemical sensing, biomedical diagnosis and therapy.

Molecular Encapsulation of Frankincense Oil (Boswellia serrata) in β-Cyclodextrin as a Preliminary of the Stability Study

Molecular encapsulation is the focus of current research because it is proven to be able to maintain and even to improve the physicochemical properties of their guest molecules. A trapping agent plays an essential role in the success of encapsulation. β-cyclodextrin (β-CD) could be one of the good trapping agents because it has a hydrophobic cavity and a hydrophilic outer surface. β-CD can interact with hydrophobic bioactive compounds as the guest molecules by trapping these compounds into the cavity of β-CD. Frankincense oil (FO) is one of the essential oils. It has been researched and utilized in various fields, but the physicochemical properties of FO make it less stable. This study explains the encapsulation of FO in β-CD. By using the coprecipitation method, this study gives pure crystal, and the efficiency of encapsulation is 78%. The diffraction pattern shown in the ICs identified the pattern of diffraction in crystals with a sharp peak of diffraction, and most of these peaks showed patterns of diffraction in β-CD. The absorption intensity of the pure CD was only 2.5, but after inserting the FO in its cavity, the intensity changed to 2.7 - 2.9. It shows that there is an interaction between the non-covalent part of β-CD and bioactive molecules, which are also known as hosts - guests inclusion complexes (ICs). The results confirmed as well that the ICs formed is more stable as the increase in the boiling point of the ICs in the range of 280-295oC.

Phase solubility and thermoanalytical studies of the inclusion complex formation between curcumin and hydroxypropyl-β-cyclodextrin in hydroalcoholic solutions

Curcumin (CURC) is endowed with many pharmacological properties, among these anti-inflammatory, antioxidant, antimicrobial, and anticancer activity. Unfortunately, CURC is basically water-insoluble and undergoes a rapid photodegradation, chemical degradation, and metabolism. CURC stability and solubility can be improved by the complexation with cyclodextrins, which are cyclic oligosaccharides with a hydrophilic outer surface and a lipophilic cavity. Thus, in this work, the formation of the inclusion complex between the semisynthetic hydroxypropyl-β-cyclodextrin (HPβCD) and CURC has been studied by means of phase solubility, differential scanning calorimetry and isothermal calorimetry experiments to assess the formation, stoichiometry and affinity constant of the obtained inclusion complexes. The thermodynamics of the complex formation has been studied in different hydroalcoholic solutions and the experiments have been performed at physiological and acidic pH to verify the effect of the ionization state on the efficacy of complex formation. Results show the relevance in the choice of the pH, solvent, and mixing time on the formation of the inclusion complex between active drug(s) and HPβCD.

Preparation and Characterization of an Electrospun PLA-Cyclodextrins Composite for Simultaneous High-Efficiency PM and VOC Removal

Electrospinning is known to be a facile and effective technique to fabricate fibers of a controlled diameter-distribution. Among a multitude of polymers available for the purpose, the attention should be addressed to the environmentally compatible ones, with a special focus on sustainability. Polylactic acid (PLA) is a widespread, non-toxic polymer, originating from renewable sources and it can degrade into innocuous products. While the production of fibrous membranes is attractive for airborne particles filtration applications, their impact on the removal of gaseous compounds is generally neglected. In this study, electrospun PLA-based nanofibers were functionalized with cyclodextrins, because of their characteristic hydrophobic central cavity and a hydrophilic outer surface, in order to provide adsorptive properties to the composite. The aim of this work is to investigate a hybrid composite, from renewable sources, for the combined filtration of particulate matter (PM) and adsorption of volatile organic compounds (VOCs). Results show how their inclusion into the polymer strongly affects the fiber morphology, while their attachment onto the fiber surface only positively affects the filtration efficiency.

Selective and Regenerable Surface Based on β-Cyclodextrin for Low-Density Lipoprotein Adsorption.

Cyclodextrins (CDs) are a family of cyclic oligosaccharides, whose unique hydrophilic outer surface and lipophilic central cavity facilitate the formation of inclusion complexes with various biomolecules, such as cholesterol and phospholipids, via multi-interactions. Low-density lipoprotein (LDL) is the main carrier of cholesterol in bloodstream and is associated with the progression of atherosclerosis. The surface of LDL is composed of a shell of phospholipids monolayer containing most of the free unesterified cholesterol as well as the single copy of apolipoprotein B-100. To date, various LDL adsorbents have been fabricated to interact with the biomolecules on LDL surface. Owing to its elegant structure, CD is considered to be a promising choice for preparation of more economical and effective LDL-adsorbing materials. Therefore, in this study, interaction between β-CD and LDL in solution was investigated by dynamic light scattering, circular dichroism, and ultraviolet spectroscopy. Further, a supramolecular surface based on β-CD was simply prepared by self-assembled monolayer on gold surface. The effect of hydrogen bond and the cavity of β-CD on the interaction between β-CD and LDL was particularly explored by surface plasmon resonance (SPR) analysis. The SPR results showed that such β-CD-modified surface exhibited good selectivity and could be largely regenerated by sodium dodecyl sulfate wash. This study may extend the understanding of the interaction between LDL and LDL adsorbent or the design and development of more efficient and lower-cost LDL adsorbents in the future.

Self-assembly of one-side-functionalized graphene nanosheets in bilayered superstructures for drug delivery

In this article, we describe the one-side functionalization of graphene nanosheets with hydrophilic catechol-bearing pyrrolidine rings. For this purpose, we used, for the first time, a solvothermal alternative of 1,3 dipolar cycloaddition of azomethine ylide. To achieve asymmetrical reaction, graphene nanosheets were initially and during reaction deposited on glass substrate. The result of one-side functionalization of graphene was the formation of amphiphilic few-layered graphene nanosheets. The modified side becomes hydrophilic due to the attachment of catechols, while the nonmodified side remains hydrophobic. In the literature, there are limited examples of functionalized graphene with different sides, the so-called Janus-type graphenes. These amphiphilic graphene nanosheets dispersed in water were self-organized in bilayer superstructures, with hydrophilic outer surface and hydrophobic internal space. The later can host hydrophobic molecules such as anticancer drugs and could be used in drug delivery systems. As an example, camptothecin, a drug practically insoluble in water, was used here to show that it can be transferred to water phase using graphene as transporter.

Physicochemical properties of β-cyclodextrin solutions and precipitates prepared from injectable vehicles

β-Cyclodextrin (β-CyD) is cyclic oligosaccharide of a glucopyranose, containing a relatively hydrophobic central cavity and hydrophilic outer surface. However, the usefulness of β-CyD is limited owing to its low aqueous solubility whereas we found that its apparent high solubility was evident in some injectable solvents including 2-pyrrolidone (PYR), N-methyl pyrrolidone (NMP) and dimethyl sulfoxide (DMSO). Therefore, in the present study, the physicochemical properties of the 30–60% w/w β-CyD in PYR, NMP and DMSO were investigated such as viscosity, water resistant, matrix formation rate and syringeability. The higher the concentration of β-CyD resulted in the increased viscosity and the higher force and energy of syringeability. β-CyD in PYR gave the highest viscosity which contributed to the lowest syringeability while β-CyD in DMSO exhibited the highest syringeability. The β-CyD in DMSO and NMP exhibited the higher rate of matrix formation. β-CyD in PYR showed the highest water resistant for phase separation while β-CyD in NMP gave the faster de-mixing rate compared to that from PYR. The difference in physicochemical properties of β-CyD dried ppts studied by scanning electron microscope (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) revealed that there was partial complexation of β-CyD with respective solvents. Both solution and precipitate characteristic properties will be useful for using β-CyD in further investigation as matrix material dissolved in the injectable vehicles as the in situ forming gel for periodontitis treatment.