Microneedles can penetrate the skin barrier to deliver drugs without touching the nociceptive nerves， to effectively increase the efficiency of transdermal drug delivery and improve patient compliance. Exosomes have multiple physiological functions and good biocompatibility， and are natural nanoscale drug carriers. This paper reviews the pathways and advantages of exosomes combined with microneedles for the treatment of diseases， and describes the current research status of exosome microneedle drug delivery system in various diseases. Exosome microneedles can be divided into two categories： （1） exosomes as therapeutic agents， their unique physiological origin can effectively avoid the toxicity and immunogenicity of conventional drugs and other problems； combined with microneedles directly in the specific medication site can greatly improve the metabolic consumption of oral drug delivery and patient compliance of injection drug delivery. （2） Exosomes as drug carriers， their natural vesicle structure and endogenous characteristics can protect the metabolism of foreign drugs in the body and enhance the targeting； combined with microneedles can effectively solve the problem of transdermal delivery of drugs with high efficacy but poor stability. Exosome microneedle drug delivery system is still in the laboratory stage， but it has shown great development prospects in repairing spinal cord injury， promoting diabetic ulcer wound healing， germinating， intervening myocardial infraction， relieving chronic pain and other diseases.

ObjectiveTo investigate the effects of the volatile oil of Linderae Radix on the apoptosis and autophagy of human gastric cancer cell line AGS， and to explore the regulatory role of adenosine monophosphate-activated protein kinase （AMPK）/mammalian target of rapamycin （mTOR） signaling pathway in this process. MethodThe volatile oil of Linderae Radix was extracted by steam distillation， and the effect of the volatile oil on the viability of AGS cells was detected by thiazolyl tetrazolium （MTT） colorimetry. The optimal intervention dose and time were determined according to the half maximal inhibitory concentration （IC₅₀） for subsequent research. The blank， low， medium， and high-dose volatile oil （0， 15， 30， 60 mg·L^-1） groups and the positive drug cyclophosphamide （CTX， 350 mg·L^-1） group were designed. AGS cells were treated with different doses of volatile oil for 48 h. The changes in cell proliferation， cycle， and migration were measured by colony formation assay， flow cytometry， and cell scratch test， respectively. Hematoxylin-eosin （HE） staining was employed to observe the changes of cell morphology， Annexin-V/propidium iodide （PI） double staining to measure the apoptosis， and acridine orange （AO） staining to measure the autophagy level of the cells. Western blotting was employed to determine the expression of the autophagy effectors Beclin-1， p62， microtubule-associated protein 1-light chain 3 （LC3）， B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， cleaved Caspase-3， cleaved poly ADP-ribose polymerase （PARP）， adenosine monophosphate-activated protein kinase （AMPK）， phosphorylated AMPK （p-AMPK）， mTOR， and phosphorylated mTOR （p-mTOR）. ResultCompared with the blank group， 24 h and 48 h of intervention with the volatile oil of Linderae Radix inhibited the viability of AGS cells in a concentration- and time-dependent manner （P<0.05， P<0.01）. Compared with the blank group， the volatile oil decreased the cell proliferation and migration （P<0.05， P<0.01） and blocked the AGS cell cycle in G₂/M phase （P<0.05， P<0.01） in a concentration-dependent manner. The cells treated with the volatile oil became spherical and smaller， with the formation of apoptotic bodies and increased apoptosis rate （P<0.05， P<0.01）. As the dose of the volatile oil increased， the number of autophagosomes increased and the red fluorescence gradually enhanced， indicating the elevated level of autophagy. Compared with the blank group， different doses of volatile oil up-regulated the protein levels of Beclin-1， LC3 Ⅱ/LC3 Ⅰ， cleaved Caspase-3， cleaved PARP， Bax/Bcl-2， and AMPK （P<0.05， P<0.01） and down-regulated the protein levels of p62 and p-mTOR （P<0.05， P<0.01）. ConclusionThe volatile oil of Linderae Radix induces the apoptosis and exerts the autophagy-mediated growth inhibition of AGS cells by regulating the AMPK/mTOR signaling pathway.

Exosome is a kind of vesicle secreted by a variety of cells with lipid bilayer membrane structure， which has good biocompatibility， high targeting and high stability， and is a natural nanoscale drug carrier with great development potential in drug delivery system. In this paper， exosomes and their properties， exosome drug delivery pathways and methods， the design strategy of engineered exosome drug delivery systems for targeted disease therapy， and the application of exosome drug delivery systems in the treatment of a variety of diseases were reviewed. Exosome drug delivery pathways could be divided into two categories： exogenous and endogenous. Common exosome drug delivery methods included electroporation， co-incubation， and ultrasound. Engineered exosome drug delivery system can further improve drug loading and enhance drug targeting. The main way of engineering is to modify exosome surface through genetic engineering technology， physical modification， chemical modification， etc. Exosome drug delivery system provides a new idea for targeted therapy of arthritis， tumor， brain and other diseases.

Autophagy is mediated by multiple molecules and pathways. In cardiovascular diseases， autophagy can play a role through key signaling pathways such as phosphoinositide 3-kinase （PI3K）/protein kinase B （Akt）/mammalian target of rapamycin （mTOR）， adenosine monophosphate-activated protein kinase （AMPK）/mTOR， mitogen-activated protein kinases （MAPK）， p53， Wnt/β-catenin， etc. Traditional Chinese medicine （TCM） monomers for promoting blood circulation and removing blood stasis such as hydroxysafflor yellow A， ginsenoside Rb1， salidroside， ligustrin， curcumin， etc.， and TCM prescription and preparations such as Huangqi baoxin decoction， Taohong siwu decoction， Tongxinluo capsule， Shuangshen ningxin capsule， Suxiao jiuxin pills， etc. can regulate autophagy through the above-mentioned key signaling pathways， thereby alleviating the progression of cardiovascular diseases.