Non-ionic small amphiphile based nanostructures for biomedical applications

Luminogenic and Bactericidal Studies of an Acrylonitrile-Based AIEgen

We have synthesized an aggregation-induced emissive molecule that exhibits promising photophysical characteristics. The aggregating aptitude is demonstrated by binary solvent mixture and it is emissive in both solution and solid state. The luminogenic characteristics are employed in creating fluorescent inks as well as for the detection of nitro antibiotics in biofluids and in solid support. Moreover, the acrylonitrile-based compound is bactericidal tested on E. coli and B. subtilis.

Recent progress on polySarcosine as an alternative to PEGylation: Synthesis and biomedical applications

Biotherapeutic PEGylation to prolong action of medications has gained popularity over the last decades. Various hydrophilic natural polymers have been developed to tackle the drawbacks of PEGylation, such as its accelerated blood clearance and non-biodegradability. Polypeptoides, such as polysarcosine (pSar), have been explored as hydrophilic substitutes for PEG. pSar has PEG-like physicochemical characteristics such as water solubility and no reported cytotoxicity and immunogenicity. This review discusses pSar derivatives, synthesis, characterization approaches, biomedical applications, in addition to the challenges and future perspectives of pSar based biomaterials as an alternative to PEG.

Adsorption Properties and Wettability of Ethoxy- and Propoxy- Derivatives of 2-Ethylhexanol as Sterically Specific Surfactant Structures

2-ethylhexanol, an oxo alcohol competitively priced on the global market, has not been explored intensively as a raw material for surfactants, due to its weak hydrophobic character. However, its sequenced propoxylation and ethoxylation yield an innovative amphiphilic structure, which exhibits unique interfacial activity. The paper presents the differences in the fractional composition of innovative surfactants derived from 2-EH alcohol prepared using alkali and dimetalcyanide catalysts, as well as examples of excellent adsorption and interfacial properties of the latter. The adsorption behavior of the synthesized compounds was explored using equilibrium surface tension (the du Noüy ring method), dynamic surface tension (the maximum gas bubble pressure method) and static/dynamic contact angle (the sessile drop method). The results from the adsorption tests conducted at the air/aqueous surfactant solution interface underwent comprehensive qualitative and quantitative analyses. Moreover, based on the experimentally obtained dynamic surface tension isotherms and the developed algorithm, the diffusion coefficients for these preparations were estimated, and it was shown that the diffusivity of these surfactants is higher compared to the commercial formulations. The study's outcomes in the testing of wettability indicate that new synthesized nonionic and anionic surfactants constitute an interesting group of amphiphiles with a wide application potential as effective wetting agents, especially in relation to the polymer surface. It should therefore be emphasized that the innovative surfactants described in this article, derived from 2-EH alcohol and prepared using dimetalcyanide catalysts, can successfully compete with conventional preparations such as ABS (Dodecylbenzenesulfonic Acid) or AES (Alcohol Ethoxysulphate) acid salts.

Design, synthesis and biological evaluation of novel cationic liposomes loaded with melphalan for the treatment of cancer

Therapeutically active lipids in drug delivery systems offer customization for enhanced pharmaceutical and biological effects, improving safety and efficacy. Biologically active N, N-didodecyl-3,4-dimethoxy-N-methylbenzenaminium lipid (Q) was synthesized and employed to create a liposome formulation (FQ) encapsulating melphalan (M) through a thin film hydration method. Synthesized cationic lipids and their liposomal formulation underwent characterization and assessment for additive anti-cancer effects on myeloma and melanoma cancer cell lines. These effects were evaluated through various studies, including cytotoxicity assessments, cell cycle arrest analysis, apoptosis measurements, mitochondrial membrane potential depolarization, DNA fragmentation, and a significant reduction in tumorigenic potential, as evidenced by a decrease in both the number and percentage area of cancer spheroids.

Tools to enable the study and translation of supramolecular amphiphiles

This tutorial review focuses on providing a summary of the key techniques used for the characterisation of supramolecular amphiphiles and their self-assembled aggregates; from the understanding of low-level molecular interactions, to materials analysis, use of data to support computer-aided molecular design and finally, the translation of this class of compounds for real world application, specifically within the clinical setting. We highlight the common methodologies used for the study of traditional amphiphiles and build to provide specific examples that enable the study of specialist supramolecular systems. This includes the use of nuclear magnetic resonance spectroscopy, mass spectrometry, X-ray scattering techniques (small- and wide-angle X-ray scattering and single crystal X-ray diffraction), critical aggregation (or micelle) concentration determination methodologies, machine learning, and various microscopy techniques. Furthermore, this review provides guidance for working with supramolecular amphiphiles in in vitro and in vivo settings, as well as the use of accessible software programs, to facilitate screening and selection of druggable molecules. Each section provides: a methodology overview - information that may be derived from the use of the methodology described; a case study - examples for the application of these methodologies; and a summary section - providing methodology specific benefits, limitations and future applications.

Importance of microbial amphiphiles: interaction potential of biosurfactants, amyloids, and other exo-polymeric-substances

Microorganisms produce a diverse group of biomolecules having amphipathic nature (amphiphiles). Microbial amphiphiles, including amyloids, bio-surfactants, and other exo-polymeric substances, play a crucial role in various biological processes and have gained significant attention recently. Although diverse in biochemical composition, these amphiphiles have been reported for common microbial traits like biofilm formation and pathogenicity due to their ability to act as surface active agents with active interfacial properties essential for microbes to grow in various niches. This enables microbes to reduce surface tension, emulsification, dispersion, and attachment at the interface. In this report, the ecological importance and biotechnological usage of important amphiphiles have been discussed. The low molecular weight amphiphiles like biosurfactants, siderophores, and peptides showing helical and antimicrobial activities have been extensively reported for their ability to work as quorum-sensing mediators. While high molecular weight amphiphiles make up amyloid fibers, exopolysaccharides, liposomes, or magnetosomes have been shown to have a significant influence in deciding microbial physiology and survival. In this report, we have discussed the functional similarities and biochemical variations of several amphipathic biomolecules produced by microbes, and the present report shows these amphiphiles showing polyphyletic and ecophysiological groups of microorganisms and hence can `be replaced in biotechnological applications depending on the compatibility of the processes.

Organic-Inorganic Porphyrinoid Frameworks for Biomolecule Sensing

Porphyrinoids and their analogous compounds play an important role in biosensing applications on account of their unique and versatile catalytic, coordination, photophysical, and electrochemical properties. Their remarkable arrays of properties can be finely tuned by synthetically modifying the porphyrinoid ring and varying the various structural parameters such as peripheral functionalization, metal coordination, and covalent or physical conjugation with other organic or inorganic scaffolds such as nanoparticles, metal-organic frameworks, and polymers. Porphyrinoids and their organic-inorganic conjugates are not only used as responsive materials but also utilized for the immobilization and embedding of biomolecules for applications in wearable devices, fast sensing devices, and other functional materials. The present review delineates the impact of different porphyrinoid conjugates on their physicochemical properties and their specificity as biosensors in a range of applications. The newest porphyrinoid types and their synthesis, modification, and functionalization are presented along with their advantages and performance improvements.

Peptide-based assembled nanostructures that can direct cellular responses

Natural originated materials have been well-studied over the past several decades owing to their higher biocompatibility compared to the traditional polymers. Peptides, consisting of amino acids, are among the most popular programable building blocks, which is becoming a growing interest in nanobiotechnology. Structures assembled using those biomimetic peptides allow the exploration of chemical sequences beyond those been routinely used in biology. In this Review, we discussed the most recent experimental discoveries on the peptide-based assembled nanostructures and their potential application at the cellular level such as drug delivery. In particular, we explored the fundamental principles of peptide self-assembly and the most recent development in improving their interactions with biological systems. We believe that as the fundamental knowledge of the peptide assemblies evolves, the more sophisticated and versatile nanostructures can be built, with promising biomedical applications.

Supramolecular self-associating amphiphiles: determination of molecular self-association properties and calculation of critical micelle concentration using a high-throughput, optical density based methodology

Supramolecular self-associating amphiphiles are a class of amphiphilic salt, the anionic component of which is 'frustrated' in nature, meaning multiple hydrogen bonding modes can be accessed simultaneously. Here we derive critical micelle concentration values for four supramolecular self-associating amphiphiles using the standard pendant drop approach and present a new high-throughput, optical density measurement based methodology, to enable the estimation of critical micelle concentrations over multiple temperatures. In addition, we characterise the low-level hydrogen bonded self-association events in the solid state, through single crystal X-ray diffraction, and in polar organic DMSO-d₆ solutions using a combination of ¹H NMR techniques. Moving into aqueous ethanol solutions (EtOH/H₂O or EtOH/D₂O (1 : 19 v/v)), we also show these amphiphilic compounds to form higher-order self-associated species through a combination of ¹H NMR, dynamic light scattering and zeta potential studies.

Fabrication of hydrolase responsive diglycerol based Gemini amphiphiles for dermal drug delivery applications

Since biocatalysts manoeuvre most of the physiological activities in living organisms and exhibit extreme selectivity and specificity, their use to trigger physicochemical change in polymeric architectures has been successfully used for targeted drug delivery. Our major interest is to develop lipase responsive nanoscale delivery systems from bio-compatible and biodegradable building blocks. Herein, we report the synthesis of four novel non-ionic Gemini amphiphiles using a chemo-enzymatic approach. A symmetrical diglycerol has been used as a core that is functionalised with alkyl chains for the creation of a hydrophobic cavity, and for aqueous solubility (polyethylene glycol) monomethyl ether (mPEG) is incorporated. Such systems can exhibit a varied self-assembly behaviour leading to the observance of different morphological structures. The aggregation behaviour of the synthesised nanocarrier was studied by dynamic light scattering (DLS) and critical aggregation concentration (CAC) measurements. The nanotransport potential of amphiphiles was investigated for hydrophobic guest molecules, i.e. Nile red, nimodipine and curcumin. Cytotoxicity of the amphiphiles was studied using HeLa and MCF7 cell lines at different concentrations, i.e. 0.05, 0.1, and 0.5 mg mL⁻¹. All nanocarriers were found to be non-cytotoxic up to a concentration of 0.1 mg mL⁻¹. Confocal laser scanning microscopy (cLSM) study suggested the uptake of encapsulated dye in the cytosol of the cancer cells within 4 h, thus implying that amphiphilic systems can efficiently transport hydrophobic drug molecules into cells. The biomedical application of the synthesised Gemini amphiphiles was also investigated for dermal drug delivery. In addition, the enzyme-mediated release study was performed that demonstrated 90% of the dye is released within three days. All these results supported the capability of nanocarriers in drug delivery systems.

Lipase responsive diglycerol based Gemini amphiphiles have been synthesized via a chemo-enzymatic approach and their application in dermal drug delivery has been explored.

Lipophilic Conjugates of Drugs: A Tool to Improve Drug Pharmacokinetic and Therapeutic Profiles

Lipophilic conjugates (LCs) of small molecule drugs have been used widely in clinical and pre-clinical studies to achieve a number of pharmacokinetic and therapeutic benefits. For example, lipophilic derivatives of drugs are employed in several long acting injectable products to provide sustained drug exposure for hormone replacement therapy and to treat conditions such as neuropsychiatric diseases. LCs can also be used to modulate drug metabolism, and to enhance drug permeation across membranes, either by increasing lipophilicity to enhance passive diffusion or by increasing protein-mediated active transport. Furthermore, such conjugation strategies have been employed to promote drug association with endogenous macromolecular carriers (e.g. albumin and lipoproteins), and this in turn results in altered drug distribution and pharmacokinetic profiles, where the changes can be 'general' (e.g. prolonged plasma half-life) or 'specific' (e.g. enhanced delivery to specific tissues in parallel with the macromolecular carriers). Another utility of LCs is to enhance the encapsulation of drugs within engineered nanoscale drug delivery systems, in order to best take advantage of the targeting and pharmacokinetic benefits of nanomedicines. The current review provides a summary of the mechanisms by which lipophilic conjugates, including in combination with delivery vehicles, can be used to control drug delivery, distribution and therapeutic profiles. The article is structured into sections which highlight a specific benefit of LCs and then demonstrate this benefit with case studies. The review attempts to provide a toolbox to assist researchers to design and optimise drug candidates, including consideration of drug-formulation compatibility.

Liquid filled hard shell capsules: Current drug delivery influencing pharmaceutical technology

PURPOSE

Gastric absorption apparently is upfront route for drug delivery as it is convenient, economic and mostly suitable for getting the desired systemic effects. Unfortunately, many traditional and newer generation drugs suffer from poor solubility and thereby have lower bioavailability. With a perspective of bringing a novel delivery system in such condition for old/existing/new drugs, liquid filled hard capsules hold promise as delivery system.

METHODS

An organized state-of-the-art literature review including patents was done to accommodate information on the innovations in technology, processes and applications in the field of liquid filling in hard shell capsules.

RESULTS

The review findings revealed the importance of understanding the impact of liquid filled hard shell capsules would have in use of complex drug molecules specially the ones sensitive to light and moisture. This technology can have diverse functions to be used for both immediate and delayed drug release. Technology point of view the band sealing in such hard-shell capsules helps in providing protection against the tampering of the filled capsule.

CONCLUSION

The review gives an insight to the understanding of progression in the technology forefront related to formulation development of liquid formulations to be filled in hard shell capsules for better therapeutic potentials and convenience to the patients.