The Yin and Yang of the protein corona on the delivery journey of nanoparticles.

Nanoparticles-based drug delivery systems have attracted significant attention in biomedical fields because they can deliver loaded cargoes to the target site in a controlled manner. However, tremendous challenges must still be overcome to reach the expected targeting and therapeutic efficacy in vivo. These challenges mainly arise because the interaction between nanoparticles and biological systems is complex and dynamic and is influenced by the physicochemical properties of the nanoparticles and the heterogeneity of biological systems. Importantly, once the nanoparticles are injected into the blood, a protein corona will inevitably form on the surface. The protein corona creates a new biological identity which plays a vital role in mediating the bio-nano interaction and determining the ultimate results. Thus, it is essential to understand how the protein corona affects the delivery journey of nanoparticles in vivo and what we can do to exploit the protein corona for better delivery efficiency. In this review, we first summarize the fundamental impact of the protein corona on the delivery journey of nanoparticles. Next, we emphasize the strategies that have been developed for tailoring and exploiting the protein corona to improve the transportation behavior of nanoparticles in vivo. Finally, we highlight what we need to do as a next step towards better understanding and exploitation of the protein corona. We hope these insights into the "Yin and Yang" effect of the protein corona will have profound implications for understanding the role of the protein corona in a wide range of nanoparticles.

Near-infrared-II photothermal ultra-small carbon dots promoting anticancer efficiency by enhancing tumor penetration.

Because of the particular environment of the tumor microenvironment, improving the deep penetration of drugs in tumor sites is a critical problem to improve the therapeutic effect of the tumor. The ultra-small nanoparticles can achieve deep tumor tissue penetration without modification, which shows tremendous significance in tumor therapy. In this work, the ultra-small permeable carbon dots (PCD) have been developed with near-infrared-II (NIR-II) window photothermal irradiation and good biocompatibility. These PCD showed multi-color fluorescence under visible light and photoacoustic signals under an excitation of 808 nm, guiding fluorescence and photoacoustic imaging for location and distribution in vitro and vivo. The PCD could penetrate the deep tissue in tumor spheroids and tissues. Meanwhile, the irradiated depth of the NIR-II window can provide sufficient photothermal energy with the deep penetration of PCD in tumor tissue to cause tumor ablation. Therefore, this PCD can be used as a safe, fluorescent, and photoacoustic imaging agent for guided NIR-II photothermal tumor therapy, which provides a new direction for the use of ultra-small carbon dots in anticancer therapy in the future.

Gold nanorods-mediated efficient synergistic immunotherapy for detection and inhibition of postoperative tumor recurrence.

Tumor recurrence after surgery is the main cause of treatment failure. However, the initial stage of recurrence is not easy to detect, and it is difficult to cure in the late stage. In order to improve the life quality of postoperative patients, an efficient synergistic immunotherapy was developed to achieve early diagnosis and treatment of post-surgical tumor recurrence, simultaneously. In this paper, two kinds of theranostic agents based on gold nanorods (AuNRs) platform were prepared. AuNRs and quantum dots (QDs) in one agent was used for the detection of carcinoembryonic antigen (CEA), using fluorescence resonance energy transfer (FRET) technology to indicate the occurrence of in situ recurrence, while AuNRs in the other agent was used for photothermal therapy (PTT), together with anti-PDL1 mediated immunotherapy to alleviate the process of tumor metastasis. A series of assays indicated that this synergistic immunotherapy could induce tumor cell death and the increased generation of CD3+/CD4+ T-lymphocytes and CD3+/CD8+ T-lymphocytes. Besides, more immune factors (IL-2, IL-6, and IFN-γ) produced by synergistic immunotherapy were secreted than mono-immunotherapy. This cooperative immunotherapy strategy could be utilized for diagnosis and treatment of postoperative tumor recurrence at the same time, providing a new perspective for basic and clinical research.

Ursodeoxycholic Acid Alters Bile Acid and Fatty Acid Profiles in a Mouse Model of Diet-Induced Obesity.

Ursodeoxycholic acid (UDCA) is a bile acid (BA) approved by the U.S. Food and Drug Administration for the treatment of primary biliary cholangitis. It is also the major active component of bear bile used in traditional Chinese medicine to reduce fever, remove toxins, and treat liver and eye ailments. In addition, UDCA and its conjugated form have been evaluated for their potential to improve symptoms of metabolic diseases, but the results have been inconclusive. To address this issue, in this study, we investigated the effects of orally administered UDCA on mice with diet-induced obesity, including the BA and free fatty acid (FFA) profiles of serum, liver, and epididymis and brown adipose tissues. We found that UDCA treatment significantly improved most metabolic indices; tauroursodeoxycholic acid (TUDCA) and taurolithocholic acid (TLCA) contents were increased in all examined tissues, whereas saturated FA levels were decreased, and n-3 polyunsaturated fatty acid (n-3 PUFA) levels were increased in most tissues. A correlation analysis showed that the concentrations of UDCA and its derivatives were positively correlated with that of n-3 PUFA. To clarify the mechanism by which UDCA alters FFA profiles, we analyzed the expression levels of genes involved in FFA biosynthesis, uptake, and oxidation and found that FFA biosynthesis and uptake were inhibited while FFA oxidation was stimulated by UDCA treatment. Additionally, amino acid-conjugated derivatives of UDCA, such as TUDCA and TLCA, altered FFA profiles by modulating FFA biosynthesis, uptake, and oxidation. These findings provide evidence that UDCA can alleviate metabolic dysfunction and could therefore be effective in the treatment of obesity.

Bone-Targeted Nanoplatform Combining Zoledronate and Photothermal Therapy To Treat Breast Cancer Bone Metastasis.

Bone metastasis, a clinical complication of patients with advanced breast cancer, seriously reduces the quality of life. To avoid destruction of the bone matrix, current treatments focus on inhibiting the cancer cell growth and the osteoclast activity through combination therapy. Therefore, it could be beneficial to develop a bone-targeted drug delivery system to treat bone metastasis. Here, a bone-targeted nanoplatform was developed using gold nanorods enclosed inside mesoporous silica nanoparticles (Au@MSNs) which were then conjugated with zoledronic acid (ZOL). The nanoparticles (Au@MSNs-ZOL) not only showed bone-targeting ability in vivo but also inhibited the formation of osteoclast-like cells and promoted osteoblast differentiation in vitro. The combination of Au@MSNs-ZOL and photothermal therapy (PTT), triggered by near-infrared irradiation, inhibited tumor growth both in vitro and in vivo and relieved pain and bone resorption in vivo by inducing apoptosis in cancer cells and improving the bone microenvironment. This single nanoplatform combines ZOL and PTT to provide an exciting strategy for treating breast cancer bone metastasis.