Fine-tuning the sequential drug release of nano-formulated mutual prodrugs dictates the combination effects

Regulation of CRISPR trans-cleavage activity by an overhanging activator

The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system exhibits extraordinary capability in the field of molecular diagnosis and biosensing, attributed to its trans-cleavage ability. The precise modulation of performance has emerged as a significant challenge in advancing CRISPR technology to the next stage of development. Herein, we reported a CRISPR/Cas12a regulation strategy based on an overhanging activator. The presence of overhanging domains in activators creates steric hindrances that have a substantial impact on the trans-cleavage activity and activation timing of Cas12a. The trans-cleavage activity of Cas12a can be finely tuned by adjusting the position, length, and complementarity of the overhanging domains. Moreover, specific structures exhibit characteristics of automatic delayed activation. The presence of overhanging domains enables precise and timely activation of Cas12a, facilitating multifunctional applications. This system effectively accomplishes dynamic regulation, programmable release of cargo, logical operations, and multi-enzyme detection. The flexibility and versatility of this simple and powerful CRISPR regulatory strategy will pave the way for expanded applications of CRISPR/Cas in biotechnology, bioengineering, and biomedicine.

Multistage microfluidic assisted Co-Delivery platform for dual-agent facile sequential encapsulation

The integration of multiple therapeutic agents within a single nano-drug carrier holds promise for advancing anti-tumor therapies, despite challenges posed by their diverse physicochemical properties. This study introduces a novel multi-stage microfluidic co-encapsulation platform designed to address these challenges. By carefully orchestrating the nano-precipitation process sequence, this platform achieves sequential encapsulation of two drugs with markedly different physicochemical characteristics. Using the multi-stage microfluidic TrH chip, hybrid nanoparticles (HNPs) loaded with paclitaxel (PTX)-simvastatin (SV), PTX-lenvatinib (LV), and SV-LV were synthesized. Unlike conventional Bulk methods and existing commercial microfluidic Tesla and Baffle chips, the HNPs produced here exhibit a core-shell structure and uniform particle size distribution, crucial for enhancing drug delivery efficacy. Notably, this method achieves nearly 100 % encapsulation efficiency for both drugs across a dual-drug feed ratio range from 1:4 to 4:1. Drug loading efficiencies were quantified for PTX-SV/HNPs (14.97 ± 1.19 %), PTX-LV/HNPs (16.58 ± 0.69 %), and SV-LV/HNPs (19.21 ± 2.38 %). PTX-SV/HNPs demonstrated sequential release characteristics of SV and PTX, as confirmed by in vitro drug release experiments. Significantly, PTX-SV/HNPs exhibited superior cytotoxicity against HepG2 cells compared to individual PTX and SV treatments, underscoring their potential in cancer therapy. In conclusion, the developed multi-stage microfluidic platform represents a robust strategy for co-encapsulating drugs with substantial physicochemical disparities, thereby offering a promising avenue for advancing multi-drug delivery in nanomedicine applications.

Copper-based metal-organic framework co-loaded doxorubicin and curcumin for anti-cancer with synergistic apoptosis and ferroptosis therapy

The combination of chemotherapy and ferroptosis therapy can greatly improve the efficiency of tumor treatment. However, ferroptosis-based therapy is limited by the unsatisfactory Fenton activity and insufficient H2O2 supply in tumor cells. In this work, a nano-drug delivery system Cur@DOX@MOF-199 NPs was constructed to combine ferroptosis and apoptosis by loading curcumin (Cur) and doxorubicin (DOX) based on the copper-based organic framework MOF-199. Cur@DOX@MOF-199 NPs decompose quickly by glutathione (GSH), releasing Cu2+, DOX and Cur. Cu2+ can deplete GSH while also being reduced to Cu+; DOX can induce apoptosis and simultaneously boost H2O2 production. Moreover, Cur enhanced the expression of intracellular heme oxygenase-1 (HO-1), for decomposing heme and releasing Fe2+, which further combined with Cu+ to catalyze H2O2 for hydroxyl radical (OH) generation, leading to the accumulation of lipid peroxide and ferroptosis. As a result, Cur@DOX@MOF-199 NPs exhibited significantly enhanced antitumor efficacy in MCF-7 tumor-bearing mouse model, suggesting this nano formulation is an excellent synergetic pathway for apoptosis and ferroptosis.

Enhancing cancer immunotherapy: Nanotechnology-mediated immunotherapy overcoming immunosuppression

Immunotherapy is an important cancer treatment method that offers hope for curing cancer patients. While immunotherapy has achieved initial success, a major obstacle to its widespread adoption is the inability to benefit the majority of patients. The success or failure of immunotherapy is closely linked to the tumor's immune microenvironment. Recently, there has been significant attention on strategies to regulate the tumor immune microenvironment in order to stimulate anti-tumor immune responses in cancer immunotherapy. The distinctive physical properties and design flexibility of nanomedicines have been extensively utilized to target immune cells (including tumor-associated macrophages (TAMs), T cells, myeloid-derived suppressor cells (MDSCs), and tumor-associated fibroblasts (TAFs)), offering promising advancements in cancer immunotherapy. In this article, we have reviewed treatment strategies aimed at targeting various immune cells to regulate the tumor immune microenvironment. The focus is on cancer immunotherapy models that are based on nanomedicines, with the goal of inducing or enhancing anti-tumor immune responses to improve immunotherapy. It is worth noting that combining cancer immunotherapy with other treatments, such as chemotherapy, radiotherapy, and photodynamic therapy, can maximize the therapeutic effects. Finally, we have identified the challenges that nanotechnology-mediated immunotherapy needs to overcome in order to design more effective nanosystems.

Regulating Drug Release Performance of Acid-Triggered Dimeric Prodrug-Based Drug Self-Delivery System by Altering Its Aggregation Structure

Dimeric prodrugs have been investigated intensely as carrier-free drug self-delivery systems (DSDSs) in recent decades, and their stimuli-responsive drug release has usually been controlled by the conjugations between the drug molecules, including the stimuli (pH or redox) and responsive sensitivity. Here, an acid-triggered dimeric prodrug of doxorubicin (DOX) was synthesized by conjugating two DOX molecules with an acid-labile ketal linker. It possessed high drug content near the pure drug, while the premature drug leakage in blood circulation was efficiently suppressed. Furthermore, its aggregation structures were controlled by fabricating nanomedicines via different approaches, such as fast precipitation and slow self-assembly, to regulate the drug release performance. Such findings are expected to enable better anti-tumor efficacy with the desired drug release rate, beyond the molecular structure of the dimeric prodrug.

Enhancing hair regeneration: Recent progress in tailoring nanostructured lipid carriers through surface modification strategies

BACKGROUND AND PURPOSE

Hair loss is a prevalent problem affecting millions of people worldwide, necessitating innovative and efficient regrowth approaches. Nanostructured lipid carriers (NLCs) have become a hopeful option for transporting bioactive substances to hair follicles because of their compatibility with the body and capability to improve drug absorption.

REVIEW APPROACH

Recently, surface modification techniques have been used to enhance hair regeneration by improving the customization of NLCs. These techniques involve applying polymers, incorporating targeting molecules, and modifying the surface charge.

KEY RESULTS

The conversation focuses on how these techniques enhance stability, compatibility with the body, and precise delivery to hair follicles within NLCs. Moreover, it explains how surface-modified NLCs can improve the bioavailability of hair growth-promoting agents like minoxidil and finasteride. Furthermore, information on how surface-modified NLCs interact with hair follicles is given, uncovering their possible uses in treating hair loss conditions.

CONCLUSION

This review discusses the potential of altering the surface of NLCs to customize them for enhanced hair growth. It offers important information for upcoming studies on hair growth.

Thermosensitive hydrogel with programmed dual-octenidine release combating biofilm for the treatment of apical periodontitis

The utilization of intracanal medicaments is an indispensable procedure in root-canal treatment. However, the conventional intracanal medicaments still need improvement regarding antimicrobial efficacy and ease of clinical operation. To address the above issues, OCT/PECT@OCT + ALK composite hydrogel characterized by programming sequential release of dual antimicrobial agents has been proposed. Thanks to the self-assemble ability of amphiphilic copolymer poly(ε-caprolactone-co-1,4,8-trioxa [4.6]spiro-9-undecanone)-poly(ethylene glycol)-poly(ε-caprolactone-co-1,4,8-trioxa[4.6]spiro-9-undecanone) (PECT), dual hydrophilic and hydrophobic antimicrobial agents could be easily encapsulated in the hydrogel system and tailored for sequential drug release for a better antibiofilm effect. The hydrophilic octenidine (Octenidine dihydrochloride, OCT-HCl) is encapsulated in the hydrophilic part of hydrogel for instantaneous elevating the drug concentration through bursting release, and the hydrophobic octenidine (Octenidine, OCT) is further loaded into the PECT nanoparticles to achieve a slower and sustained-release profile. Additionally, calcium hydroxide (Ca(OH)2) was incorporated into the system and evenly dispersed among PECT nanoparticles to create an alkaline (ALK) environment, synergistically enhancing the antibiofilm effect with higher efficiency and prolonged duration. The antibiofilm effect has been demonstrated in root-canal models and apical periodontitis rats, exhibiting superior performance compared to clinically used Ca(OH)2 paste. This study demonstrates that OCT/PECT@OCT + ALK composite thermosensitive hydrogel is a potential intracanal medicament with excellent antibiofilm effect and clinical operability.

Injectable hydrogels embedded with chitosan nanoparticles coated with hyaluronic acid for sequential release of dual drugs

An effective treatment for some disease, such as the model disease acute retinal necrosis (ARN), requires a combination of different drugs which should be administered at a certain interval. The precise sequential and long-term drug release are the critical questions. In this work, the as-prepared chitosan nanoparticles (CS-NPs) coated with hyaluronic acid (HA) were embedded in the aldehyde β-cyclodextrin (ACD)/aminated hyaluronic acid (NHA) hydrogels to synthesize injectable hydrogels loaded with dual drugs named DEX-CS-NPs/GCV-Gel and HA-DEX-CS-NPs/GCV-Gel. In the first 24 h and 48 h, the releases of DEX from DEX-CS-NPs/GCV-Gel were 128.5 % and 82.8 % faster than those from HA-DEX-CS-NPs/GCV-Gel, respectively. There was no DEX released from HA-DEX-CS-NPs/GCV-Gel at the first 7 h, which has never been reported before, although some hydrogel systems loaded with different drugs release different drugs simultaneously at different rate which have been well studied. This is a good start of a precise sequence release. The composite hydrogels possessed appropriate rheology, gel time, degradation performance, and ideal cytocompatibility. The injectable hydrogel loaded with dual drugs presenting a precise sequential and long-term release has great potential in the treatment of diseases requiring combinations of drugs being released sequentially at different treating stages.