Use of stimulatory responsive soft nanoparticles for intracellular drug delivery

Simple strategy of the use of pharmaceutically functionalized ionic liquids in a new generation of polymer nanocarriers for the combined delivery of ionic p-aminosalicylate and ampicillin

Single and dual bioactive linear poly(ionic liquid)s (PIL) were synthesized for use as nanocarriers in drug delivery systems (DDS). These PILs were obtained through the (co)polymerization of the choline-based monomeric ionic liquids (MIL) with pharmaceutical anions possessing antibacterial properties, specifically [2-(methacryloyloxy)ethyl]trimethyl-ammonium with ampicillin and p-aminosalicylate (TMAMA/AMP and TMAMA/PAS). The copolymers exhibited varying chain lengths defined by a degree of polymerization (DPn = 122-370), and differing contents of ionic fraction and drugs (TMAMA 61-92 %, AMP 61-93 % and PAS 16-21 %). These parameters were adjustable by the monomer conversion (33-92 %) and the initial ratio of comonomers. In aqueous solution, the polymer particles reached nanosizes, i.e. 190-328 nm for AMP systems and 200-235 nm for AMP/PAS systems. In the release process, the pharmaceutical anions were released through exchange by phosphate anions in PBS at pH 7.4 at 37 °C. Depending on the copolymer composition the release of AMP was attained in 72-100 % (11.1-19.5 µg/mL) within 26 h by the single drug systems, while the dual drug systems released 61-100 % of AMP (14.8-24.7 µg/mL) and 82-100 % of PAS (3.1-4.8 µg/mL) within 72 h. The effectiveness in the drug delivery of the designed TMAMA polymers seems to be promising for future applications in antibiotic therapy and the combined therapy.

Flash nanoprecipitation assisted self-assembly of ionizable lipid nanoparticles for nucleic acid delivery

Ionizable lipid nanoparticles (LNPs) have emerged as a powerful tool for the intracellular delivery of nucleic acids. Following the recent success of LNP-based siRNA therapeutics and mRNA vaccines, the use of ionizable lipids for nucleic acid delivery has tremendously increased. Here, we introduce a flash nanoprecipitation (FNP) approach using the confined impingement (CIJ) mixer to stably self-assemble ionizable LNPs. To validate this approach, we employed three clinically relevant LNP formulations containing SM102, ALC0315, and DLin-MC3-DMA as ionizable lipids. FNP-assembled LNPs showed >95% encapsulation efficiency of mRNA and siRNA payloads and particle sizes below 150 nm. SM102 or ALC0315 LNPs demonstrated efficient delivery of mRNA into immune cells in vitro and to lymphoid organs in vivo, whereas Dlin-MC3-DMA LNPs allowed effective intracellular siRNA delivery with great functional ability. The FNP technique could economically produce LNPs in smaller volumes that are highly suitable for the discovery phase.

Formulation, Characterization and In Vitro Evaluation of Mesalamine and Bifidobacterium bifidum Loaded Hydrogel Beads in Capsule System for Colon Targeted Delivery

Mesalamine is a first-line drug for the treatment of inflammatory bowel diseases. However, its premature release associated with marketed formulations leads to adverse effects like gastric trouble, vomiting, and diarrhoea. To minimize these side effects, colon-targeted drug delivery is essential. Besides conventional pharmacotherapy, bifidogenic probiotics with anti-inflammatory activity has been reported to elicit a significant impact on the remission of ulcerative colitis. Bifidogenic probiotics being acid-labile necessitate developing a gastro-resistant formulation for enhancing the delivery of viable cells to the colon. The present study was aimed at developing a fixed-dose unit dosage form of mucoadhesive hydrogel beads loaded with mesalamine and Bifidobacterium bifidum further encapsulated in Eudragit® capsules for the targeted drug delivery at colonic pH. The hydrogel beads were prepared by ionotropic gelation, with the effect of single and dual-crosslinking approaches on various formulation characteristics studied. Standard size 00 Eudragit® gastro-resistant capsules were prepared and the dried beads were filled inside the capsule shells. The formulation was then evaluated for various parameters, including physicochemical characterization, in vitro biocompatibility and anti-inflammatory activity. No interaction was observed between the drug and the polymers, as confirmed through FTIR, XRD, and DSC analysis. The mean particle size of the beads was ~ 457-485 µm. The optimized formulation showed a drug entrapment efficiency of 95.4 ± 2.58%. The Eudragit® capsule shells disintegrated in approximately 13 min at pH 7.4. The mucoadhesive hydrogel beads sustained the drug release above 18 h, with 50% of the drug released by the end of 12 h. The optimized formulation demonstrated significant (p < 0.05) gastro-resistance, biocompatibility, sustained drug release, cell viability, and anti-inflammatory activity.

Flash nanoprecipitation allows easy fabrication of pH-responsive acetalated dextran nanoparticles for intracellular release of payloads

Acetalated dextran (Ac-Dex) nanoparticles are currently of immense interest due to their sharp pH-responsive nature and high biodegradability. Ac-Dex nanoparticles are often formulated through single- or double-emulsion methods utilizing polyvinyl alcohol as the stabilizer. The emulsion methods utilize toxic organic solvents such as dichloromethane or chloroform and require multi-step processing to form stable Ac-Dex nanoparticles. Here, we introduce a simple flash nanoprecipitation (FNP) approach that utilizes a confined impinging jet mixer and a non-toxic solvent, ethanol, to form Ac-Dex nanoparticles rapidly. Ac-Dex nanoparticles were stabilized using nonionic PEGylated surfactants, D-α-Tocopherol polyethylene glycol succinate (TPGS), or Pluronic (F-127). Ac-Dex nanoparticles formed using FNP were highly monodisperse and stably encapsulated a wide range of payloads, including hydrophobic, hydrophilic, and macromolecules. When lyophilized, Ac-Dex TPGS nanoparticles remained stable for at least one year with greater than 80% payload retention. Ac-Dex nanoparticles were non-toxic to cells and achieved intracellular release of payloads into the cytoplasm. In vivo studies demonstrated a predominant biodistribution of Ac-Dex TPGS nanoparticles in the liver, lungs, and spleen after intravenous administration. Taken together, the FNP technique allows easy fabrication and loading of Ac-Dex nanoparticles that can precisely release payloads into intracellular environments for diverse therapeutic applications. pH-responsive Acetalateddextran can be formulated using nonionic surfactants, such as TPGS or F-127, for intracellular release of payloads. Highly monodisperse and stable nanoparticles can be created through the simple, scalable flash nanoprecipitation technique, which utilizes a confined impingement jet mixer.

Understanding the Mechanical Properties of Ultradeformable Liposomes Using Molecular Dynamics Simulations

Improving drug delivery efficiency to solid tumor sites is a central challenge in anticancer therapeutic research. Our previous experimental study (Guo et al., Nat. Commun. 2018, 9, 130) showed that soft, elastic liposomes had increased uptake and accumulation in cancer cells and tumors in vitro and in vivo respectively, relative to rigid particles. As a first step toward understanding how liposomes' molecular structure and composition modulates their elasticity, we performed all-atom and coarse-grained classical molecular dynamics (MD) simulations of lipid bilayers formed by mixing a long-tailed unsaturated phospholipid with a short-tailed saturated lipid with the same headgroup. The former types of phospholipids considered were 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dipalmitoleoyl-sn-glycero-3-phosphocholine (termed here DPMPC). The shorter saturated lipids examined were 1,2-diheptanoyl-sn-glycero-3-phosphocholine (DHPC), 1,2-didecanoyl-sn-glycero-3-phosphocholine (DDPC), 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). Several lipid concentrations and surface tensions were considered. Our results show that DOPC or DPMPC systems having 25-35 mol % of the shortest lipids DHPC or DDPC are the least rigid, having area compressibility moduli KA that are ∼10% smaller than the values observed in pure DOPC or DPMPC bilayers. These results agree with experimental measurements of the stretching modulus and lysis tension in liposomes with the same compositions. These mixed systems also have lower areas per lipid and form more uneven x-y interfaces with water, the tails of both primary and secondary lipids are more disordered, and the terminal methyl groups in the tails of the long lipid DOPC or DPMPC wriggle more in the vertical direction, compared to pure DOPC or DPMPC bilayers or their mixtures with the longer saturated lipid DLPC or DMPC. These observations confirm our hypothesis that adding increasing concentrations of the short unsaturated lipid DHPC or DDPC to DOPC or DPMPC bilayers alters lipid packing and thus makes the resulting liposomes more elastic and less rigid. No formation of lipid nanodomains was noted in our simulations, and no clear trends were observed in the lateral diffusivities of the lipids as the concentration, type of secondary lipid, and surface tension were varied.

Self-Luminescent Drug Delivery Vehicle: Synthesis, Self-Assembly Behavior, Cysteine-Responsive Property, and Application in the Visualization of Drug Release

Targeted drug delivery systems have gained great attention from the chemistry and biomedical fields in recent years due to the minimized harm to normal cells. When designing targeted drug delivery systems, the property of harmlessness to normal cells and the tracking ability of the whole process are quite crucial. These two characters can be brought into the related systems by applying a drug carrier that is self-luminescent and its drug release can be induced by the microenvironment of cancer cells. Therefore, the design and synthesis of drug delivery vehicles are significant for the fabrication of target drug delivery systems. Herein, we have synthesized a cysteine-responsive and fluorescent molecule, maleic acid-modified tetraphenylethylene derivative (MATPE), by a facile method. In addition, a drug delivery system with self-luminescence and cysteine-responsiveness based on the self-assembly of MATPE was fabricated. In this system, MATPE and cysteine both played dual roles as cysteine probe/drug carrier and emission-enhanced inducement/drug-release stimulus. The drug-release process was successfully realized in cancer cells and can be visualized, exhibiting great potential in the field of theranostics.

Stimuli responsive nanosonosensitizers for sonodynamic therapy

Sonodynamic therapy (SDT) has gained significant attention in the treatment of deep tumors and multidrug-resistant (MDR) bacterial infections due to its high tissue penetration depth, high spatiotemporal selectivity, and noninvasive therapeutic method. SDT combines low-intensity ultrasound (US) and sonosensitizers to produce lethal reactive oxygen species (ROS) and external damage, which is the main mechanism behind this therapy. However, traditional organic small-molecule sonosensitizers display poor water solubility, strong phototoxicity, and insufficient targeting ability. Inorganic sonosensitizers, on the other hand, have low ROS yield and poor biocompatibility. These drawbacks have hindered SDT's clinical transformation and application. Hence, designing stimuli-responsive nano-sonosensitizers that make use of the lesion's local microenvironment characteristics and US stimulation is an excellent alternative for achieving efficient, specific, and safe treatment. In this review, we provide a comprehensive overview of the currently accepted mechanisms in SDT and discuss the application of responsive nano-sonosensitizers in the treatment of tumor and bacterial infections. Additionally, we emphasize the significance of the principle and process of response, based on the classification of response patterns. Finally, this review emphasizes the potential limitations and future perspectives of SDT that need to be addressed to promote its clinical transformation.

Selective organ targeting nanoparticles: from design to clinical translation

Targeting nanoparticle is a very promising therapeutic approach that can precisely target specific sites to treat diseases. Research on nanoscale drug delivery systems has made great progress in the past few years, making targeting nanoparticles a promising prospect. However, selective targeting nanoparticles designed for specific organs still face several challenges, one of which is the unknown fate of nanoparticles in vivo. This review starts with the in vivo journey of nanoparticles and describes the biological barriers and some targeting strategies for nanoparticles to target specific organs. Then, through the collection of literature in recent years, the design of selective targeting nanoparticles for various organs is illustrated, which provides a reference strategy for people to study the design of selective organ targeting nanoparticles. Ultimately, the prospect and challenge of selective organ targeting nanoparticles are discussed by collecting the data of clinical trials and marketed drugs.

Treatment with FAP-targeted zinc ferrite nanoparticles for rheumatoid arthritis by inducing endoplasmic reticulum stress and mitochondrial damage

Rheumatoid arthritis (RA) is a common chronic inflammatory disease characterized by the proliferation of fibroblast-like synoviocytes (FLS), pannus development, cartilage, and bone degradation, and, eventually, loss of joint function. Fibroblast activating protein (FAP) is a particular product of activated FLS and is highly prevalent in RA-derived fibroblast-like synoviocytes (RA-FLS). In this study, zinc ferrite nanoparticles (ZF-NPs) were engineered to target FAP+ (FAP positive) FLS. ZF-NPswere discovered to better target FAP+ FLS due to the surface alteration of FAP peptide and to enhance RA-FLS apoptosis by activating the endoplasmic reticulum stress (ERS) system via the PERK-ATF4-CHOP, IRE1-XBP1 pathway, and mitochondrial damage of RA-FLS. Treatment with ZF-NPs under the influence of an alternating magnetic field (AMF) can significantly amplify ERS and mitochondrial damage via the magnetocaloric effect. It was also observed in adjuvant-induced arthritis (AIA) mice that FAP-targeted ZF-NPs (FAP-ZF-NPs) could significantly suppress synovitis in vivo, inhibit synovial tissue angiogenesis, protect articular cartilage, and reduce M1 macrophage infiltration in synovium in AIA mice. Furthermore, treatment of AIA mice with FAP-ZF-NPs was found to be more promising in the presence of an AMF. These findings demonstrate the potential utility of FAP-ZF-NPs in the treatment of RA.