Small-cell lung cancer (SCLC) is characterized as an aggressive tumor with brain metastasis. Although preventing SCLC metastasis to the brain is immensely important for survival, the molecular mechanisms of SCLC cells penetrating the blood–brain barrier (BBB) are largely unknown. Recently, visfatin has been considered as a novel pro-inflammatory adipocytokine involved in various cancers. Herein, we present evidence that elevated levels of visfatin in the serum of SCLC patients were associated with brain metastasis, and visfain was increased in NCI-H446 cells, a SCLC cell line, during interacting with human brain microvascular endothelial cells (HBMEC). Using in vitro BBB model, we found that visfatin could promote NCI-H446 cells migration across HBMEC monolayer, while the effect was inhibited by knockdown of visfatin. Furthermore, our findings indicated that CC chemokine ligand 2 (CCL2) was involved in visfatin-mediated NCI-H446 cells transendothelial migtation. Results also showed that the upregulation of CCL2 in the co-culture system was reversed by blockade of visfatin. In particular, visfatin-induced CCL2 was attenuated by specific inhibitor of PI3K/Akt signaling in NCI-H446 cells. Taken together, we demonstrated that visfatin was a prospective target for SCLC metastasis to brain, and understanding the molecular mediators would lead to effective strategies for inhibition of SCLC brain metastasis.

Skin wound healing is a highly regulated biological process that requires the coordinated activity of multiple cell types. However, this process can be significantly impaired by factors such as metabolic diseases and infections, posing ongoing challenges for current treatment strategies. As a critical defense mechanism for cells and organisms against external threats, antimicrobial peptides (AMPs) hold great potential to enhance both the rate and quality of healing in both acute and chronic wounds. AMPs play a crucial role in promoting skin wound healing through mechanisms such as keratinocyte migration and proliferation, collagen synthesis and tissue remodeling, promotion of angiogenesis, immunomodulatory effects and broad-spectrum antimicrobial activity. Moreover, structural modifications and optimized delivery systems have further enhanced the stability and efficacy of AMPs. This paper explores the mechanisms by which AMPs aid in the healing of damaged skin and reviews the types of AMPs in clinical trials, providing a foundation for their development and clinical application.

Peptide drug development has emerged as a prominent area in pharmaceutical research due to its high specificity and therapeutic potential. However, their biological activity, stability, and bioavailability are significantly influenced by interactions with counter-ions, which electrostatically bind to charged residues on peptide surfaces. This review systematically examines the multifaceted roles of counter-ions in modulating peptide structure and function. Counter-ions are classified into organic/inorganic and anionic/cationic categories, with their selection critically impacting peptide solubility, conformational stability, and activity. Inorganic counter-ions could enhance structural integrity, while organic counter-ions could mitigate toxicity risks. Notably, counter-ions can induce secondary structural transitions, directly affecting biological efficacy. Furthermore, counter-ions play pivotal roles in drug delivery systems, including nanoemulsions, self-emulsifying formulations, and lipid-based nanoparticles, where hydrophobic ion pairing improves encapsulation efficiency and oral bioavailability. In chromatography, ion-pairing reagents optimize peptide separation but may compromise mass spectrometry compatibility. Emerging analytical techniques, such as capillary electrophoresis and liquid chromatography–tandem mass spectrometry (LC-MS/MS), enhance counter-ion detection precision, addressing challenges in pharmaceutical quality control. Despite advancements, gaps remain in understanding ion-specific binding mechanisms and long-term safety profiles. This review underscores the necessity of tailoring counter-ion selection to balance efficacy, stability, and biocompatibility. Future research should prioritize elucidating molecular interaction dynamics and developing safer, high-affinity counter-ions to overcome current limitations in peptide drug development.

Ovarian cancer remains a therapeutic challenge due to high recurrence rates and chemoresistance, necessitating novel agents from natural sources. In our pr