Superior intratumoral penetration of paclitaxel nanodots strengthens tumor restriction and metastasis prevention.

Recently discovered intratumoral diffusion resistance, together with poor solubility and nontargeted distribution of chemotherapeutic drugs, has significantly impaired the performance of cancer treatments. By developing a well-designed droplet-confined/cryodesiccation-driven crystallization approach, we herein report the successful preparation of nanocrystallites of insoluble chemotherapeutic drug paclitaxel (PTX) in forms of nanodots (NDs, ≈10 nm) and nanoparticles (NPs, ≈70 nm) with considerably high drug loading capacity. Superficially coated Pluronic F127 is demonstrated to endow the both PTX nanocrystallites with excellent water solubility and prevent undesired phagocyte uptake. Further decoration with tumor-penetrating peptide iRGD, as expected, indiscriminatively facilitates tumor cell uptake in traditional monolayer cell culture model. On the contrary, distinctly enhanced performances in inward penetration and ensuing elimination of 3D multicellular tumor spheroids are achieved by iRGD-NDs rather than iRGD-NPs, revealing the significant influence of particle size variation in nanoscale. In vivo experiments verify that, although efficient tumor enrichment is achieved by all nanocrystallites, only the iRGD-grafted nanocrystallites of ultranano size realize thorough intratumoral delivery and reach cancer stem cells, which are concealed inside the tumor core. Consequently, much strengthened restriction on progress and metastasis of orthotopic 4T1 mammary adenocarcinoma is achieved in murine model, in sharp contrast to commercial PTX formulation Taxol.

Surface-engineered graphene navigate divergent biological outcomes toward macrophages.

The "nano-bio" interface profoundly shapes the interaction between cells and nanomaterials and can even decide a cell's fate. As a nascent two-dimensional material, graphene has many unique attributes and is proposed to be a promising candidate for biomedical applications. Thus, for graphene-based applications, it is necessary to clarify how the graphene surface navigates biological outcomes when encountering "janitorial" cells (macrophages). For this purpose, we synthesized nanographene oxide (nGO) and engineered the surface with polyethylene glycol (PEG), bovine serum albumin (BSA), and poly(ether imide) (PEI). In contrast to pristine nGO, decoration with PEG and BSA hindered endocytosis and improved their benignancy toward macrophages. Contrarily, nGO-PEI commenced with favorable endocytosis but then suffered stagnation due to compromised macrophage viability. To unravel the underlying mechanisms regulating these diverse macrophage fates, we built a stepwise analysis. Compared to the others, nGO-PEI tended to interact electrostatically with mitochondria after their cellular internalization. Such an unexpected encounter disrupted the normal potential and integrity of mitochondria and then elicited an alteration in reactive oxygen species and cytochrome c. These responses further initiated the activation of the caspase family and ultimately dictated cells to undergo apoptosis. The advances described above will complement our knowledge of graphene functionality and serve to guide its application in biotechnological applications.

Programmed co-delivery of paclitaxel and doxorubicin boosted by camouflaging with erythrocyte membrane.

Combination chemotherapy has been proven promising for cancer treatment, but unsatisfactory therapeutic data and increased side effects slow down the development in the clinic. In this study, we develop an effective approach to co-encapsulate a hydrophilic-hydrophobic chemotherapeutic drug pair (paclitaxel and doxorubicin) into magnetic O-carboxymethyl-chitosan nanoparticles. To endow them with the ability of programmed delivery, these carriers are further camouflaged with an Arg-Gly-Asp anchored erythrocyte membrane. Compared with the traditional polyethylene glycol coating method, this biomimetic decoration strategy is demonstrated to be superior in prolonging circulation time, improving tumor accumulation, facilitating tumor uptake, and tuning intracellular fate. These outstanding properties enable the as-designed nanodevice to exhibit greater tumor growth inhibition ability and much lower side effects than the combined use of commercial formulations.