Prostate cancer is a common cancer in elderly males. Significant progress has been made in the drug therapies for prostate cancer in recent years. However, side effects are still problems that have not been overcome by the currently used anti-prostate cancer drugs. Novel technologies can be applied to reduce or even eliminate the side effects of drugs. An aptamer may be a sequence of nucleic acids or peptides that can specifically recognize proteins or cells. Taking advantage of this feature, scientists have designed aptamer–drug delivery systems for the development of anti-prostate cancer agents. Theoretically, these aptamer–drug delivery systems can specifically recognize prostate cancer cells and then induce cell death without attacking normal cells. We collected the relevant literature in this field and found that at least nine compounds have been prepared as aptamer–drug delivery systems to evaluate their precise anti-prostate cancer effects. However, the currently studied aptamer–drug delivery systems have not yet entered the market due to defects. Here, we analyze the published data, summarize the characteristics of these delivery systems, and propose ways to promote their application, thus promoting the development of the aptamer–drug delivery systems against prostate cancer.

Pinctada fucata meat is the main by-product of the pearl harvesting industry. It is rich in nutrition, containing a lot of protein and peptides, and holds significant value for both medicine and food. In this study, a new active protein was discovered and expressed heterogeneously through bioinformatics analysis. It was then identified using Western blot, molecular weight, and mass spectrometry. The antibacterial activity, hemolysis activity, antioxidant activity, and Angiotensin-Converting Enzyme II (ACE2) inhibitory activity were investigated. An unknown functional protein was screened through the Uniprot protein database, and its primary structure did not resemble existing proteins. It was an α-helical cationic polypeptide we named PFAP-1. The codon-optimized full-length PFAP-1 gene was synthesized and inserted into the prokaryotic expression vector pET-30a. The induced expression conditions were determined with a final isopropyl-β-d-thiogalactoside (IPTG) concentration of 0.2 mM, an induction temperature of 15 °C, and an induction time of 16 h. The recombinant PFAP-1 protein, with low endotoxin and sterility, was successfully prepared. The recombinant PFAP-1 protein exhibited strong antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) in vitro, and the diameter of the inhibition zone was 15.99 ± 0.02 mm. Its minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were 37.5 μg/mL and 150 μg/mL, respectively, and its hemolytic activity was low (11.21%) at the bactericidal concentration. The recombinant PFAP-1 protein significantly inhibited the formation of MRSA biofilm and eradicated MRSA biofilm. It also demonstrated potent 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) scavenging activity with a half-maximal inhibitory concentration (IC₅₀) of 40.83 μg/mL. The IC₅₀ of ACE2 inhibition was 5.66 μg/mL. Molecular docking results revealed that the optimal docking fraction of PFAP-1 protein and ACE2 protein was −267.78 kcal/mol, with a confidence level of 0.913. The stable binding complex was primarily formed through nine groups of hydrogen bonds, three groups of salt bridges, and numerous hydrophobic interactions. In conclusion, recombinant PFAP-1 can serve as a promising active protein in food, cosmetics, or medicine.

Marine lectins are a group of proteins that possess specific carbohydrate recognition and binding domains. They exhibit various activities, including antimicrobial, antitumor, antiviral, and immunomodulatory effects. In this study, a novel galectin-binding lectin gene named PFL-96 (GenBank: OQ561753.1) was cloned from Pinctada fucata. The PFL-96 gene has an open reading frame of 324 base pairs (bp) and encodes a protein comprising 107 amino acids. The protein has a molecular weight of 11.95 kDa and an isoelectric point of 9.27. It contains an N-terminal signal peptide and a galactose-binding lectin domain. The sequence identity to lectin proteins from fish, echinoderms, coelenterates, and shellfish ranges from 31.90 to 40.00 %. In the phylogenetic analysis, it was found that the PFL-96 protein is closely related to the lectin from Pteria penguin. The PFL-96 recombinant protein exhibited coagulation activity on 2 % rabbit red blood cells at a concentration of ≥8 μg/mL. Additionally, it showed significant hemolytic activity at a concentration of ≥32 μg/mL. The PFL-96 recombinant protein exhibited significant antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Candida albicans, and Vibrio alginolyticus, with minimum inhibitory concentrations (MIC) of 4, 8, 16, and 16 μg/mL, respectively. The minimum bactericidal concentrations (MBC) were determined to be 8, 16, 32, and 32 μg/mL, respectively. Furthermore, the PFL-96 recombinant protein exhibited inhibitory effects on the proliferation of Hela tumor cells, HepG2 tumor cells, and C666-1 tumor cells, with IC₅₀ values of 7.962, 8.007, and 9.502 μg/mL, respectively. These findings suggest that the recombinant protein PFL-96 exhibits significant bioactivity in vitro, contributing to a better understanding of the active compounds found in P. fucata. The present study establishes a fundamental basis for further investigation into the mechanism of action and structural optimization of the recombinant protein PFL-96. The aim is to develop potential candidates for antibacterial and anti-tumor agents.

The aim of this study was to achieve the high secretion and expression of thymosin β4 derived from Pinctada fucata in Pichia pastoris, as well as to investigate its antibacterial properties and biological effects in promoting wound healing. The recombinant thymosin β4 protein (rTβ4) exhibited no hemolytic activity on rabbit red blood cells and demonstrated significant antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), with a minimum inhibitory concentration (MIC) of 25 μg/mL. It effectively inhibited bacterial growth and disrupted the cell wall and membrane structure of the bacteria. In the Sprague Dawley (SD) rat wound healing model, the wound healing rate in the rTβ4 treatment groups (at concentrations of 12.5 and 25 μg/mL) was significantly higher than that in the control group (p < 0.05), and the healing effect was comparable to that of the positive control group (Kangfu Xin solution, KFX). The histopathological study demonstrated that rTβ4 could reduce the infiltration of inflammatory cells and promote the proliferation and re-epithelialization of granulation tissue. In conclusion, this study successfully achieved the high expression of thymosin β4 derived from Pinctada fucata in Pichia pastoris and validated its antibacterial and wound healing potential through both In vitro and In vivo experiments.