pH-Sensitive Biomimetic Nanosystem Based on Large-Pore Mesoporous Silica Nanoparticles with High Hyaluronidase Loading for Tumor Deep Penetration

Loading hyaluronidase (Hyal) in a nanocarrier is a potent strategy to degrade the tumor extracellular matrix for tumor deep penetration and enhanced tumor therapy. Herein, a pH-sensitive biomimicking nanosystem with high Hyal loading, effective tumor targeting, and controllable release is constructed. Specifically, cationic mesoporous silica nanoparticles (CMSNs) with large pores 13.52 nm in diameter were synthesized in a one-pot manner by adding N-[3-trimethoxysilylpropyl]-N,N,N-trimethylammonium to a reversed microemulsion reaction system. The Hyal loading rate was as high as 19.47% owing to matched pore size and the cationic surface charge. Subsequently, a pH-sensitive biomimetic hybrid membrane (pHH) composed of pH-sensitive liposome (pHL), red blood cell membrane, and pancreatic cancer cell membrane was camouflaged on the pHL-coated and doxorubicin/Hyal-loaded CMSNs (shortened as DHCM). The DHCM@pHL@pHH is stable at neutral pH while it releases the payloads smoothly in the tumor acidic microenvironment. Consequently, it can escape from macrophage clearance, be specifically taken up by pancreatic cancer cells, and efficiently accumulate at the tumor site. More importantly, it can penetrate deeply in pancreatic tumors with a tumor growth inhibition ratio of 80.46%. The nanosystem is biocompatible and has potential for clinical transformation, and the nanocarrier is promisingly applicable as a platform for encapsulation of various macromolecules for smart and tumor-targeted delivery.

Dual-Responsive Polyprodrug Nanoparticles with Cascade-Enhanced Magnetic Resonance Signals for Deep-Penetration Drug Release in Tumor Therapy

Smart transformable nanocarriers are promising to treat deep-seated diseases but require adaptable diagnostic/imaging potency to reflect the morphology change and therapeutic feedback, yet their design and synthesis remains challenging. Herein, stimuli-responsive polyprodrug nanoparticles (SPNs) are formulated from the co-assembly of negatively charged corona and positively charged polyprodrug cores, exhibiting high loading content of camptothecin (CPT, ∼28.6 wt %) tethered via disulfide linkages in the core. SPNs are sequentially sensitive to tumor acidic condition and elevated reductive milieu in the cytosol for deep-penetration drug delivery. Upon accumulation at acidic tumor sites, SPNs dissociate to release smaller positively charged polyprodrug nanoparticles, which efficiently enter deep-seated tumor cells to trigger high-dosage parent CPT release in the reductive cytosolic milieu. Meanwhile, the polyprodrug cores of SPNs labeled with DTPA(Gd), a magnetic resonance imaging contrast agent, can trace the cascade degradation and biodistribution of SPNs as well as the resulting intracellular CPT release. The longitudinal relaxivity of SPNs increases stepwise in the above two processes. The size-switchable polyprodrug nanoparticles exhibit remarkable tumor penetration and noteworthy tumor inhibition in vitro and in vivo, which are promising for endogenously activated precision diagnostics and therapy.

Structure-Switchable DNA Programmed Disassembly of Nanoparticles for Smart Size Tunability and Cancer-Specific Drug Release

The size of the nanocarrier is considered one of the most important issues for its therapeutic effect. Thus, an intelligent nanocarrier with dynamic size has been explored as a promising approach to fulfill the requirements for both efficient accumulation according to the enhanced penetration and retention (EPR) effect and deep penetration into tumor tissue. Herein, structure-switchable triplex DNA was modified on gold nanoparticles (AuNPs) to investigate its potential to modulate the nanoparticle dynamic disassembly process among the tumor microenvironment. We report that the pH-sensitive triplex DNA exhibited outstanding sensitivity and size tunability in triggering the disassembly of AuNP clusters into smaller sizes among the tumor acidic environment, leading to better permeability both in vitro and in vivo. By further combination of the telomerase-sensitive hairpin DNA loaded with chemotherapy drug doxorubicin (DOX), a cancer-specific intracellular drug-release function was also realized, resulting in a precise treatment effect and lower toxicity on normal cells. Through comodification of these two structure-switchable DNA chains on AuNPs and construction of nanoparticle assemblies with proper size, programmed disassembly and drug-release function in tissue and cell level, respectively, were successfully combined and eventually facilitated a highly efficient nanodrug transportation process, from tumor accumulation to deep penetration and precise cancer chemotherapy. The study provided the prospect of utilizing functionalized DNA in optimization of nanocarrier delivery efficiency.