Editorial: Nanotechnology in Traditional Medicines and Natural Products

Institute for Chemical Biology and Biosensing, and College of Life Sciences, Qingdao University, Qingdao, China, Institute of Tropical Medicine and Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China, College of Engineering and Applied Sciences, Nanjing University, Nanjing, China, Department of Chemistry, Northwestern University, Evanston, IL, United States, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, China

nanoformulation. The latest progresses in this research area have been reviewed by Wu et al. and included in this topic (Wu et al.).
Nanotechnology has also benefited the development of traditional medicine by targeted delivery and controlled release. By attaching ligands such as folic acid, hyaluronic acid, cRGD, transferrin, and aptamers, nanoparticles are prone to accumulate in cancer cells through cell internalization processes, hence help reduce the drug dosage and minimize the side effects on normal tissues (Muhamad et al., 2018;Niu et al.). Cell-derived membranes such as cancer cell membranes provide original complex biological entities that are difficult to replicate artificially. These entities not only help avoid body clearance by immune recognition but also allow specific binding with homotypic tumor cells (Harris et al., 2019). Mesoporous silica nanoparticle loading with quercetin (QT) and wrapping in cancer cell membranes have been reported by Huang et al. and included in this topic for enhanced tumor targeting and radiotherapy, which is a good example that biomimetic nanotechnology helps in natural nanomedicine drug delivery (Huang et al.). Many cancer cells are found to have a lower pH and a higher glutathione level; thus, smart responsive nanoformulation has been designed for drug release at target sites upon stimuli such as pH and redox (Jiang et al.). Versatile formulation technology also allows co-delivery of multiple drugs, since multiple active ingredients are usually employed in traditional medicine. It also facilitates the combination of chemotherapy with photothermo-and photodynamic therapy (Chen et al.). Futher details await your reference in this topic for the nanotechnology in traditional medicines and natural products.
Last decades have witnessed the prosperity of immunotherapy in cancer research, which is fundamentally different from traditional chemotherapy or targeted therapy. It activates hosts' own immune systems to fight against cancer cells, avoiding exposure of normal cells and tissues directly to the toxicity of drugs. Mounting evidence has shown the great potential of natural products and their derivatives in cancer immunotherapy (Deng et al., 2020). For example, Liu et al. found a water-soluble polysaccharide isolated from Polyporus umbellatus Fries, which has significant immune activity and increases the secretion of inflammatory cytokines. The results show that this polysaccharide may be valuable in bladder cancer treatment (Liu et al.). Other typical examples of natural products with anticancer immunologic activity include polyphenols, cardiotonic steroids, and terpenoids (Deng et al., 2020). We hope the abovementioned content included in this topic is useful for exploring the potential of tradition medicine and natural products in immunotherapy in the future.
Drug delivery by nanocarriers has advantages such as targeted delivery, ease of controlled release, higher stability, and delivery efficiency. Moreover, it makes diagnosis and therapy in-one-go possible, offering chances to relieve patients' pain. Although a wealth of evidence has supported the curative effect of natural product and traditional medicine in disease treatment and cancer therapy, there remain some critical problems and challenges before being widely commercialized. First, most of the research on the nanomedicine of natural product still in the infancy phase of laboratory testing. More work to explore and evaluate their action mechanism and regulation pathway scientifically is needed. In addition, herbal and traditional medicines often adopt complex prescription, which contains more than two active ingredients, making it more difficult to study their curative mechanism. Third, while a plenty of Western nanomedicines such as Doxil, Emend, and Cimzia have been FDA-approved and marketed, there is still a long way to go for traditional medicine and natural products. Standard clinical trials and systematic evaluation are suggested to be established first. More promising results are expected after the merge of the nanomedicine technology and natural products.

AUTHOR CONTRIBUTIONS
RZ drafted the manuscript, and other authors discussed and revised the manuscript.

ACKNOWLEDGMENTS
RZ thanks the National Science Foundation for Young Scientists of China (Grant No. 21904076) and the Research Foundation for talents of Qingdao University. FL thanks the National Natural Science Foundation of China (21807018).