Near-IR Remote Release from Assemblies of Liposomes and Nanoparticles

A DFT approach for finding therapeutic potential of graphyne as a nanocarrier in the doxorubicin drug delivery to treat cancer

In the present work, the drug-loading efficacy of graphyne (GYN) for doxorubicin (DOX) drug is investigated for the first time by using density functional theory (DFT). Doxorubicin drug is effective in the cure of numerous types of cancer including bone cancer, gastric, thyroid, bladder, ovarian, breast, and soft tissue cancer. Doxorubicin drug prevents the cell division process by intercalating in the double-helix of DNA and stopping its replication. The optimized, geometrical, energetic, and excited-state characteristics of graphyne (GYN), doxorubicin drug (DOX), and doxorubicin-graphyne complex (DOX@GYN complex) are calculated to see how effective it is as a carrier. The DOX drug interacted with GYN with an adsorption-energy of -1.57 eV (gas-phase). The interaction of GYN with DOX drug is investigated using NCI (non-covalent interaction) analysis. The findings of this analysis showed that the DOX@GYN complex has weak forces of interaction. Charge transfer from doxorubicin drug to GYN during DOX@GYN complex formation is described by charge-decomposition analysis and HOMO-LUMO analysis. The increased dipole-moment (8.41 D) of the DOX@GYN in contrast with therapeutic agent DOX and GYN indicated that the drug will move easily in the biochemical system. Furthermore, the photo-induced electron-transfer process is explored for excited states, and it reveals that upon interaction, fluorescence-quenching will occur in the complex DOX@GYN. In addition, the influence of the positive and negative charge states on the GYN and DOX@GYN is also considered. Overall, the findings indicated that the GYN could be exploited as an effective drug-transporter for the delivery of doxorubicin drug. Investigators will be inspired to look at another 2D nanomaterials for drug transport applications as a result of this theoretical work.

Controlled supramolecular interactions for targeted release of Amiodarone drug through Graphyne to treat cardiovascular diseases: An in silico study

In the current study, the drug loading ability of graphyne (GY) for the amiodarone (AMD) drug is investigated for the first time. The efficacy of GY as a carrier for amiodarone (a cardiovascular drug) is evaluated by calculating its electronic, energetic, optimized, and excited state properties with help of the density functional theory (DFT). The AMD drug interacted with the GY molecule with an adsorption energy of about -0.19 eV (gas-phase) and -1.92 eV (aqueous phase), suggesting that the AMD@GY complex is stable in water-phase. The HOMO (highest-occupied molecular-orbital) of the AMD@GY complex is concentrated on the AMD drug while the LUMO (lowest-unoccupied molecular-orbital) is centralized on GY with absolute charge separation, indicating charge transfer will occur between AMD and GY. The charge-transfer process is further studied with the aid of charge-decomposition analysis (CDA). The non-covalent interaction analysis (NCI) exposed that non-covalent forces exist between the GY carrier and AMD drug. These non-covalent forces between AMD drug and GY carrier play a significant role in drug unloading at the targeted or diseased site. Likewise, the calculations at excited-state, charge-state (+1 and -1) influence on GY and AMD@GY complex structures, and photo-induced electron transfer analysis (PET) are also studied for the graphyne-based drug-delivery system. According to PET and electron-hole analysis, fluorescence-quenching will occur upon interaction. Overall, it is concluded that graphyne can be exploited as a drug carrier for amiodarone drug delivery. Researchers will be fascinated to look at alternative 2D nanomaterials for drug delivery applications as a result of this theoretical work.

Harnessing Ultrasound for Targeting Drug Delivery to the Brain and Breaching the Blood–Brain Tumour Barrier

Despite significant advances in developing drugs to treat brain tumours, achieving therapeutic concentrations of the drug at the tumour site remains a major challenge due to the presence of the blood–brain barrier (BBB). Several strategies have evolved to enhance brain delivery of chemotherapeutic agents to treat tumours; however, most approaches have several limitations which hinder their clinical utility. Promising studies indicate that ultrasound can penetrate the skull to target specific brain regions and transiently open the BBB, safely and reversibly, with a high degree of spatial and temporal specificity. In this review, we initially describe the basics of therapeutic ultrasound, then detail ultrasound-based drug delivery strategies to the brain and the mechanisms by which ultrasound can improve brain tumour therapy. We review pre-clinical and clinical findings from ultrasound-mediated BBB opening and drug delivery studies and outline current therapeutic ultrasound devices and technologies designed for this purpose.

Release of bioactive compounds from delivery systems by stimuli-responsive approaches; triggering factors, mechanisms, and applications

Recent advances in emerging nanocarriers and stimuli-responsive (SR) delivery systems have brought about a revolution in the food and pharmaceutical industries. SR carriers are able to release the encapsulated bioactive compounds (bioactives) upon an external trigger. The potential of releasing the loaded bioactives in site-specific is of great importance for the pharmaceutical industry and medicine that can deliver the cargo in an appropriate condition. For the food industry, release of encapsulated bioactives is considerably important in processing or storage of food products and can be used in their formulation or packaging. There are various stimuli to control the favorite release of bioactives. In this review, we will shed light on the effect of different stimuli such as temperature, humidity, pH, light, enzymatic hydrolysis, redox, and also multiple stimuli on the release of encapsulated cargo and their potential applications in the food and pharmaceutical industries. An overview of cargo release mechanisms is also discussed. Furthermore, various alternatives to manipulate the controlled release of bioactives from carriers and the perspective of more progress in these SR carriers are highlighted.

Computational study of therapeutic potential of phosphorene as a nano-carrier for drug delivery of nebivolol for the prohibition of cardiovascular diseases: a DFT study

Density functional theory (DFT) calculations were utilized to assess the drug delivery efficiency of phosphorene carrier for nebivolol drug to treat cardiovascular diseases. The optimized structures, excited state, and electronic properties of nebivolol, phosphorene, and nebivolol-phosphorene (nebivolol-PH) complex were considered to determine the drug delivery ability of phosphorene at the target site. The increased dipole moment (6.08 D) results in the higher solubility of the complex in polar solvents (water). Weak interactive forces between nebivolol and phosphorene were demonstrated by the non-covalent interaction (NCI) plot that facilitated the offloading of nebivolol at the targeted area. The analysis of frontier molecular orbitals (FMOs) revealed that during excitation, the charge was transferred from nebivolol as a higher occupied molecular orbital (HOMO) to phosphorene as a lower unoccupied molecular orbital (LUMO). Thus, the charge-transfer process was further studied by charge decomposition analysis (CDA). The calculated results at the excited state for the nebivolol-PH complex exhibited that the maximum wavelength (λmax) was red-shifted by 6 nm in the gas phase. The electron-hole theory and photoinduced electron transfer (PET) processes were carried out for the exploration of different excited states of the complex. Additionally, phosphorene with + 1 and - 1 charge states indicated the minor structural changes and provide the stable nebivolol-PH complex. This theoretical study also investigated that phosphorene can be exploited as an effective carrier for the delivery of a therapeutic agent as nebivolol to treat cardiovascular diseases. This work will also encourage the researchers to investigate the other 2D nanoparticles as a nano-drug delivery system (NDDS).

Degradable pH and redox dual responsive nanoparticles for efficient covalent drug delivery

Hydrophobic drug paclitaxel was modified into a polymerizable monomer and subsequently copolymerized with pH-sensitive monomers and redox-sensitive disulfide-based cyclic monomers.

SERS and Cryo-EM Directly Reveal Different Liposome Structures during Interaction with Gold Nanoparticles

The combination of gold nanoparticles with liposomes is important for nano- and biotechnology. Here, we present direct, label-free characterization of liposome structure and composition at the site of its interaction with citrate-stabilized gold nanoparticles by surface-enhanced Raman scattering (SERS) and cryogenic electron microscopy (cryo-EM). Evidenced by the vibrational spectra and cryo-EM, the gold nanoparticles destroy the bilayer structure of interacting liposomes in the presence of a high amount of citrate, while at lower citrate concentration the nanoparticles interact with the surface of the intact liposomes. The spectra of phosphatidylcholine and phosphatidylcholine/sphingomyelin liposomes show that at the site of interaction the lipid chains are in the gel phase. The SERS spectra indicate that cholesterol has strong effects on the contacts of the vesicles with the nanoparticles. By combining cryo-EM and SERS, the structure and properties of lipid-nanoparticle composites could be tailored for the development of drug delivery systems.

Liposomes assembled from a dual drug-tailed phospholipid for cancer therapy

We report a novel dual drug-tailed phospholipid which can form liposomes as a combination of prodrug and drug carrier. An amphiphilic dual chlorambucil-tailed phospholipid (DCTP) was synthesized by a straightforward esterification. With two chlorambucil molecules as hydrophobic tails and one glycerophosphatidylcholine molecule as a hydrophilic head, the DCTP, a phospholipid prodrug, undergoes assembly to form a liposome without any additives by the thin lipid film technique. The DCTP liposomes, as an effective carrier of chlorambucil, exhibited a very high loading capacity and excellent stability. The liposomes had higher cytotoxic effects to cancer cell lines than free DCTP and chlorambucil. The in vivo antitumor activity assessment indicated that the DCTP liposomes could inhibit the tumor growth effectively. This novel strategy of dual drug-tailed phospholipid liposomes may be also applicable to other hydrophobic anticancer drugs which have great potential in cancer therapy.

The self-assembly of anticancer camptothecin-dipeptide nanotubes: a minimalistic and high drug loading approach to increased efficacy

20-(S)-Camptothecin (CPT)-conjugated dipeptides are reported that preassemble into nanotubes with diameters ranging from 80-120 nm. These nanoassemblies maintain a high (∼47 %) drug loading and exhibit greater drug stability (i.e., resistance to lactone hydrolysis), and consequently greater efficacy against several human cancer cells (HT-29, A549, H460, and H23) in vitro compared with the clinically used prodrug irinotecan. A key and defining feature of this system is the use of the CPT-conjugated dipeptide as both the drug and precursor to the nanostructured carrier, which simplifies the overall fabrication process.

Chaotropic-anion-induced supramolecular self-assembly of ionic polymeric micelles

Traditional micelle self-assembly is driven by the association of hydrophobic segments of amphiphilic molecules forming distinctive core-shell nanostructures in water. Here we report a surprising chaotropic-anion-induced micellization of cationic ammonium-containing block copolymers. The resulting micelle nanoparticle consists of a large number of ion pairs (≈60,000) in each hydrophobic core. Unlike chaotropic anions (e.g. ClO4(-)), kosmotropic anions (e.g. SO4(2-)) were not able to induce micelle formation. A positive cooperativity was observed during micellization, for which only a three-fold increase in ClO4(-) concentration was necessary for micelle formation, similar to our previously reported ultra-pH-responsive behavior. This unique ion-pair-containing micelle provides a useful model system to study the complex interplay of noncovalent interactions (e.g. electrostatic, van der Waals, and hydrophobic forces) during micelle self-assembly.

Construction of thermal- and light-responsive liposomes noncovalently decorated with gold nanoparticles

GNP–DPPC, a gold nanoparticle-decorated DPPC liposome complex, can release encapsulated dyes upon heating or illumination. GNP–DPPC also has a faster thermal response and higher critical leakage temperature than liposomes.

Biocompatible magnetic liposomes for temperature triggered drug delivery

Thermosensitive magnetic liposomes (TSMLs) that serve as carriers for controlled drug release are fabricated. The TSMLs are stable below 39 °C and most drugs (5-(and-6)-carboxylfluorescein: 68% and doxorubicin: 90%) release within 1 h at 42 °C. Furthermore, TSMLs could deliver the anticancer drugs into cells to induce cell apoptosis.

Intracellular uptake, transport, and processing of gold nanostructures

The emerging field of nanomedicine requires better understanding of the interface between nanotechnology and medicine. Better knowledge of the nano-bio interface will lead to better tools for diagnostic imaging and therapy. In this review, recent progress in understanding of how size, shape, and surface properties of nanoparticles (NPs) affect intracellular fate of NPs is discussed. Gold nanostructures are used as a model system in this regard since their physical and chemical properties can be easily manipulated. The NP-uptake is dependent on the physiochemical properties, and once in the cell, most of the NPs are trafficked via an endo-lysosomal path followed by a receptor-mediated endocytosis process at the cell membrane. Within the size range of 2-100 nm, Gold nanoparticles (GNPs) of diameter 50 nm demonstrate the highest uptake. Cellular uptake studies of gold nanorods (GNRs) show that there is a decrease in uptake as the aspect ratio of GNRs increases. Theoretical models support the size- and shape-dependent NP-uptake. The intracellular transport of targeted NPs is faster than untargeted NPs. The surface ligand and charge of NPs play a bigger role in their uptake, transport, and organelle distribution. Exocytosis of NPs is dependent on size and shape as well; however, the trend is different compared to endocytosis. GNPs are now being incorporated into polymer and lipid based NPs to build multifunctional devices. A multifunctional platform based on gold nanostructures, with multimodal imaging, targeting, and therapeutics; hold the possibility of promising directions in medical research.

On the origin of primitive cells: from nutrient intake to elongation of encapsulated nucleotides

Recent major discoveries in membrane biophysics hold the key to a modern understanding of the origin of life on Earth. Membrane bilayer vesicles have been shown to provide a multifaceted microenvironment in which protometabolic reactions could have developed. Cell-membrane-like aggregates of amphiphilic molecules capable of retaining encapsulated oligonucleotides have been successfully created in the laboratory. Sophisticated laboratory studies on the origin of life now show that elongation of the DNA primer takes place inside fatty acid vesicles when activated nucleotide nutrients are added to the external medium. These studies demonstrate that cell-like vesicles can be sufficiently permeable to allow for the intake of charged molecules such as activated nucleotides, which can then take part in copying templates in the protocell interior. In this Review we summarize recent experiments in this area and describe a possible scenario for the origin of primitive cells, with an emphasis on the elongation of encapsulated nucleotides.