Development and evaluation of exemestane-loaded lyotropic liquid crystalline gel formulations

Lipidic lyotropic liquid crystals: Insights on biomedical applications

Liquid crystals (LCs) possess unique physicochemical properties, translatable into a wide range of applications. To date, lipidic lyotropic LCs (LLCs) have been extensively explored in drug delivery and imaging owing to the capability to encapsulate and release payloads with different characteristics. The current landscape of lipidic LLCs in biomedical applications is provided in this review. Initially, the main properties, types, methods of fabrication and applications of LCs are showcased. Then, a comprehensive discussion of the main biomedical applications of lipidic LLCs accordingly to the application (drug and biomacromolecule delivery, tissue engineering and molecular imaging) and route of administration is examined. Further discussion of the main limitations and perspectives of lipidic LLCs in biomedical applications are also provided. STATEMENT OF SIGNIFICANCE: Liquid crystals (LCs) are those systems between a solid and liquid state that possess unique morphological and physicochemical properties, translatable into a wide range of biomedical applications. A short description of the properties of LCs, their types and manufacturing procedures is given to serve as a background to the topic. Then, the latest and most innovative research in the field of biomedicine is examined, specifically the areas of drug and biomacromolecule delivery, tissue engineering and molecular imaging. Finally, prospects of LCs in biomedicine are discussed to show future trends and perspectives that might be utilized. This article is an ampliation, improvement and actualization of our previous short forum article "Bringing lipidic lyotropic liquid crystal technology into biomedicine" published in TIPS.

The efficacy of Origanum majorana nanocubosomal systems in ameliorating submandibular salivary gland alterations in streptozotocin-induced diabetic rats

Diabetes mellitus is a challenging health problem. Salivary gland dysfunction is one of its complications. Current treatments possess numerous adverse effects. Therefore, herbal extracts have emerged as a promising approach for safe and effective treatment. However, they are required in large doses to achieve the desired effect. Accordingly, Origanum majorana extract (OE) was incorporated into nano-sized systems to enhance its biological effects at lower dosages. OE was standardized against rosmarinic acid (RA) and then loaded into nano-cubosomal (NC) systems via a 2³ full-factorial design. Two optimum nano-systems at different drug loads (2.08 or 1.04 mg-RA/mL) were selected and assessed in vivo to compare their effects in streptozotocin-induced diabetic rats against conventional OE (2.08 mg-RA/mL). Blood glucose was evaluated weekly. Submandibular salivary glands were processed for histopathological examination and nuclear factor-erythroid 2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1), and p38-MAPK gene expression analysis. NC systems were successfully prepared and optimized where the optimum systems showed nano-sized vesicles (210.4–368.3 nm) and high zeta potential values. In vivo results showed a significant lower blood glucose in all treated groups, with an exceptional reduction with NC formulations. Marked histopathological improvement was observed in all OE-treated groups, with OE-NC4 (2.08 mg-RA/mL) demonstrating the best features. This was supported by RT-PCR; where the OE-NC4 group recorded the highest mean value of Nrf2 and the least mean values of Keap1 and p38-MAPK, followed by OE-NC3 and OE groups. In conclusion, OE-loaded NC enhanced the anti-hyperglycemic effect of OE and ameliorated diabetic gland alterations compared to conventional OE. Thus, cubosomal nano-systems could be anticipated as potential carriers for the best outcome with OE.

Highly sensitive SERS assay of genetically modified organisms in maize via a nanoflower substrate coupled with hybridization chain reaction amplification

A novel biosensor based on a high-density “hot spot” SERS substrate coupled with HCR amplification strategy was developed for the ultrasensitive detection of genetically modified organisms in maize.

Smart phase transformation system based on lyotropic liquid crystalline@hard capsules for sustained release of hydrophilic and hydrophobic drugs

Smart phase transformation systems@hard capsule (SPTS@hard capsule) based on lyotropic liquid crystalline (LLC) were developed for oral sustained release in this study. Doxycycline hydrochloride (DOXY) and meloxicam (MLX) were used as hydrophilic and hydrophobic model drug, respectively. Two systems were added with different additives, that is, gelucire 39/01, PEG 1000 and Tween 80 to adjust their melting point and release profiles. The phase transformation of these systems could be triggered by water as well as temperature. They could spontaneously transform into cubic phase or hexagonal phase when coming across with water, to achieve the 24 h sustained release profile. In addition, the obtained systems could switch between semisolid state and liquid state when temperature changed within room temperature and body temperature, which facilitated the phase transformation in gastrointestinal tract and during their encapsulation into hard capsules. LLC-based SPTS@hard capsule revealed potential for the industrialization of its oral administration on account of its drugs accommodation with different solubility, controllable release profile and simple preparation process.

Thermoresponsive gating membranes embedded with liquid crystal(s) for pulsatile transdermal drug delivery: An overview and perspectives

Due to the circadian rhythm regulation of almost every biological process in the human body, physiological and biochemical conditions vary considerably over the course of a 24-h period. Thus, optimal drug delivery and therapy should be effectively controlled to achieve the desired therapeutic plasma concentrations and therapeutic drug responses at the required time according to chronopharmacological concepts, rather than continuous maintenance of constant drug concentrations for an extended time period. For many drugs, it is not always necessary to constantly deliver a drug into the human body under disease conditions due to rhythmic variations. Pulsatile drug delivery systems (PDDSs) have been receiving more attention in pharmaceutical development by providing a predetermined lag period, followed by a fast or rate-controlled drug release after application. PDDSs are characterized by a programmed drug release, which may release a drug at repeatable pulses to match the biological and clinical needs of a given disease therapy. This review article focuses on thermoresponsive gating membranes embedded with liquid crystals (LCs) for transdermal drug delivery using PDDS technology. In addition, the principal rationale and the advanced approaches for the use of PDDSs, the marketed products of chronotherapeutic DDSs with pulsatile function designed by various PDDS technologies, pulsatile drug delivery designed with thermoresponsive polymers, challenges and opportunities of transdermal drug delivery, and novel approaches of LC systems for drug delivery are reviewed and discussed. A brief overview of all academic research articles concerning single LC- or binary LC-embedded thermoresponsive membranes with a switchable on-off permeation function through topical application by an external temperature control, which may modulate the dosing interval and administration time according to the therapeutic needs of the human body, is also compiled and presented. In the near future, since thermal-based approaches have become a well-accepted method to enhance transdermal delivery of different water-soluble drugs and macromolecules, a combination of the thermal-assisted approach with thermoresponsive LCs membranes will have the potential to improve PDDS applications but still poses a great challenge.

Advancement of Lipid-Based Nanocarriers and Combination Application with Physical Penetration Technique

On account of the advantages of transdermal delivery and the application situation of transcutaneous technology in transdermal delivery, the article critically comments on nanosystems as permeation enhancement model. Nanosystems possess great potential for transcutaneous drug delivery. This review focuses on recent advances in lipid-based nanocarriers, including liposome, transfersomes, ethosomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers and combination application of the lipid-based nanocarriers with microneedle, iontophoresis, electroporation and sonophoresis in the field for the development of the transdermal drug delivery system. We attempted to give an overview of lipid-based nanocarriers with the aim to improve transdermal and dermal drug delivery. A special focus is given to the nanocarrier composition, characteristic and interaction mechanisms through the skin. Recent combination applications of lipid-based nanocarriers with the physical penetration technology demonstrate the superiority of the combined use of nanocarriers and physical methods in drug penetration enhancement compared to their single use. In the future, lipidbased nanocarriers will play a greater role in the field of transdermal and dermal drug delivery.

Dynamic Light Scattering and Zeta Potential Studies of Ceria Nanoparticles

A Cerium (IV) oxide nanoparticle (nanoceria) is widely used in different applications such as biomedicine and catalysis due to its unique structural, morphological and catalytic properties. In this report, the dispersion of nanoceria in both aqueous and non-aqueous (methanol and ethanol) media were studied. Adsorption-desorption processes were observed upon addition of different classes of surfactants such as citric acid (CA), cetrimonium bromide (CTAB) and diethanolamine (DEA). Stable dispersions were obtained in both aqueous, non-aqueous and electrolyte assisted media with the overall mechanism being hydrolysis, dissolution and adsorption. XRD, FE-SEM, FTIR and DLS have been used in the present study to characterize the nanoceria and to quantitatively analyze their average particle size distributions in a unique electrolyte mixture of (0.1 M NaOH/ 65% HNO3:H2O, 1:1 v/v) which has not been reported previously. The surface charge study was carried out across a wide pH range between 1.4 – 9.6 and the isoelectric points (IEP) with respect to 15 ml H2O and 50 ml H2O dispersed phases occurred at a pH of about 6.5 and 6.7 respectively. The present study could be useful in a wide range of applications including nanoparticle synthesis, stabilization, and adsorption of toxic materials, biomedical and pharmaceutical.