Alzheimer’s disease (AD) is the most common neurodegenerative disease in the elderly worldwide. However, the complexity of AD pathogenesis leads to discrepancies in the understanding of this disease, and may be the main reason for the failure of AD drug development. Fortunately, many ongoing preclinical and clinical studies will continually open up avenues to unravel disease mechanisms and guide strategies for AD diagnosis and drug development. For example, immunotherapeutic strategies targeting amyloid-β (Aβ) and tau proteins were once deemed almost certainly effective in clinical treatment due to the excellent preclinical results. However, the repeated failures of clinical trials on vaccines and humanized anti-Aβ and anti-tau monoclonal antibodies have resulted in doubts on this strategy. Recently, a new anti-Aβ monoclonal antibody (Aducanumab) has been approved by the US Food and Drug Administration, which brings us back to the realization that immunotherapy strategies targeting Aβ may be still promising. Meanwhile, immunotherapies based on other targets such as tau, microglia and gut-brain axis are also under development. Further research is still needed to clarify the forms and epitopes of targeted proteins to improve the accuracy and effectiveness of immunotherapeutic drugs. In this review, we focus on the immunotherapies based on Aβ, tau and microglia and their mechanisms of action in AD. In addition, we present up-to-date advances and future perspectives on immunotherapeutic strategies for AD.
Photodynamic therapy (PDT) of cancer is limited by tumor hypoxia. Platinum nanoparticles (nano‐Pt) as a catalase‐like nanoenzyme can enhance PDT through catalytic oxygen supply. However, the cytotoxic activity of nano‐Pt is not comprehensively considered in the existing methods to exert their multifunctional antitumor effects. Here, nano‐Pt are loaded into liposomes via reverse phase evaporation. The clinical photosensitizer verteporfin (VP) is loaded in the lipid bilayer to confer PDT activity. Murine macrophage cell membranes are hybridized into the liposomal membrane to confer biomimetic and targeting features. The resulting liposomal system, termed “nano‐Pt/VP@MLipo,” is investigated for chemophototherapy in vitro and in vivo in mouse tumor models. At the tumor site, oxygen produced by nano‐Pt catalyzation improves the VP‐mediated PDT, which in turn triggers the release of nano‐Pt via membrane permeabilization. The ultrasmall 3–5 nm nano‐Pt enables better penetration in tumors, which is also facilitated by the generated oxygen gas, for enhanced chemotherapy. Chemophototherapy with a single injection of nano‐Pt/VP@MLipo and light irradiation inhibits the growth of aggressive 4T1 tumors and their lung metastasis, and prolongs animal survival without overt toxicity.
Hyperactivated Ras regulates many oncogenic pathways in several malignant human cancers including glioblastoma and it is an attractive target for cancer therapies. Ras activation in cancer cells drives protein internalization via macropinocytosis as a key nutrient-gaining process. By utilizing this unique endocytosis pathway, here we create a biologically inspired nanostructure that can induce cancer cells to ‘drink drugs’ for targeting activating transcription factor-5 (ATF5), an overexpressed anti-apoptotic transcription factor in glioblastoma. Apolipoprotein E3-reconstituted high-density lipoprotein is used to encapsulate the siRNA-loaded calcium phosphate core and facilitate it to penetrate the blood–brain barrier, thus targeting the glioblastoma cells in a macropinocytosis-dependent manner. The nanostructure carrying ATF5 siRNA exerts remarkable RNA-interfering efficiency, increases glioblastoma cell apoptosis and inhibits tumour cell growth both in vitro and in xenograft tumour models. This strategy of targeting the macropinocytosis caused by Ras activation provides a nanoparticle-based approach for precision therapy in glioblastoma and other Ras-activated cancers.
COVID-19, an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread throughout the world. China has achieved rapid containment of this highly infectious disease following the principles of early detection, early quarantine and early treatment with integrated traditional Chinese and Western medicine. The inclusion of traditional Chinese medicine (TCM) in the Chinese protocol is based on its successful historic experience in fighting against pestilence. Current findings have shown that the Chinese medicine can reduce the incidence of severe or critical events, improve clinical recovery and help alleviate symptoms such as cough or fever. To date there are over 133 ongoing registered clinical studies on TCM/integrated traditional Chinese and Western medicine. The three Chinese patent medicines (Lianhua Qingwen Keli/Jiaonang (Forsythiae and Honeysuckle Flower Pestilence-Clearing Granules/Capsules), Jinhua Qinggan Keli (Honeysuckle Flower Cold-Relieving Granules) and Xuebijing (Stasis-Resolving & Toxin-Removing) Injection were officially approved by the National Medical Products Administration to list COVID-19 as an additional indication. The pharmacological studies have suggested that Chinese medicine is effective for COVID-19 probably through its host-directed regulation and certain antiviral effects.