This article provides a brief overview of DNA vaccines. First, the basic DNA vaccine design strategies are described, then specific issues related to the industrial production of DNA vaccines are discussed, including the production and purification of DNA products such as plasmid DNA, minicircle DNA, minimalistic, immunologically defined gene expression (MIDGE) and Doggybone™. The use of adjuvants to enhance the immunogenicity of DNA vaccines is then discussed. In addition, different delivery routes and several physical and chemical methods to increase the efficacy of DNA delivery into cells are explained. Recent preclinical and clinical trials of DNA vaccines for COVID-19 are then summarized. Lastly, the advantages and obstacles of DNA vaccines are discussed.

Conventional chemotherapeutic drugs have significant limitations. For example, tumors may develop resistance, cancers may relapse after treatment, and the drugs may induce secondary malignancies in the treatment of metastatic cancer. There is still a great need for drugs that are able to destroy cancer cells selectively, that is, to effectively treat slow-growing and dormant cells without being affected by chemoresistance mechanisms. A growing number of studies indicate that peptides may be beneficial for drug discovery and development. Peptides offer minimal immunogenicity, excellent tissue penetrability, low-cost manufacturability, and ease of modification for enhancing in vivo stability and biological activity, properties which make them ideal candidates for cancer treatment. This review highlights recent advances in and future prospects for the application of peptides as therapeutic agents for cancer therapy. We discuss the application of peptides in cancer therapy, alone and in combination with other peptides or small-molecule chemotherapeutic drugs, for use in targeted cancer therapy. Furthermore, we consider the use of peptides as a carrier for targeted molecular imaging in the diagnosis and follow-up treatment of cancer. This account also reviews the challenges of using peptide drugs and ways to overcome these limitations. The results obtained in studies presented in this paper indicate that peptides are promising candidates for targeted cancer therapy.

Figure S2. Determination of relative binding affinity and specificity by flow cytometry of selected Cy3-labelled aptamers for A: HEK-293 (as EpCAM negative cell line), B and C: CT-26 and HCT-116 (as EpCAM positive cell line) respectively. The fluorescence shifts in the selected Cy3-labelled-aptamers cell lines compared to the unstained each control cell lines exhibited high affinity of aptamers to the CT-26 and HCT-116 cancer cell lines, while the aptamers showed no binding affinity to the HEK-293 EpCAM negative cell line.

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The novel pandemic of coronavirus infection (COVID-19) has been linked with coagulopathy and thromboembolic events, causing limb loss and finally death. The present report describes a case of upper limb ischemia in a patient with COVID-19 infection, who lacked conventional risk factors for acute limb ischemia (ALI). An 83-year-old man with intraluminal thrombus and the occlusion of the axillary and brachial arteries, ceasing blood supply to the distal part of the body, was tested positive for the COVID-19 infection. The patient received therapeutic anticoagulation and underwent open thromboembolectomy, which failed to save the patient's life. The link between COVID-19 and thromboembolism remains unknown and needs further studies to be disclosed.