Erythrocytes (red blood cells, RBCs) are the most abundant circulating cells in the blood and have been widely used in drug delivery systems (DDS) because of their features of biocompatibility, biodegradability, and long circulating half-life. Accordingly, a "camouflage" comprised of erythrocyte membranes renders nanoparticles as a platform that combines the advantages of native erythrocyte membranes with those of nanomaterials. Following injection into the blood of animal models, the coated nanoparticles imitate RBCs and interact with the surroundings to achieve long-term circulation. In this review, the biomimetic platform of erythrocyte membrane-coated nano-cores is described with regard to various aspects, with particular focus placed on the coating mechanism, preparation methods, verification methods, and the latest anti-tumor applications. Finally, further functional modifications of the erythrocyte membranes and attempts to fuse the surface properties of multiple cell membranes are discussed, providing a foundation to stimulate extensive research into multifunctional nano-biomimetic systems.

We previously discovered that Xiaozhang Tie (XZT) was helpful for cirrhotic ascites, with obvious abdominal distention relief, suggesting that it may improve gastrointestinal (GI) motility. However, the underlying mechanisms of GI motility in cirrhotic ascites are unclear. Here, we aimed to discover explored the effect of XZT on GI motility in animal cirrhotic ascites and probed the action mechanism affecting GI motility by regulating the stem cell factor (SCF)/c-kit pathway in interstitial cells of Cajal (ICCs) and GI hormones. First, rat models of cirrhotic ascites were developed and then divided randomly into the following three subgroups: model control, XZT group, and mosapride group. The efficacy of XZT on treating cirrhotic ascites was evaluated on the basis of ascites weight and volume, 24 h urine volume, and feces water content. GI motility of the cirrhotic model, intestine propulsion, and gastric residue were detected using the migration distance of ink in vivo, and the frequency of contraction and tension of isolated gastric and jejunal muscle strips were measured after incubation with XZT extracts. Serum GI hormone content, including motilin (MTL), substance P (SP), somatostatin (SS), and vasoactive intestinal polypeptide were assayed. Subsequently, ICCs were isolated from jejunum, and primarily cultured ICCs were incubated with and without XZT and SCF. The cell vitality of the ICCs was measured. A whole-cell patch recording technique was used to record the current of K⁺ and Na⁺ channels in the ICC membrane. Expressions of c-kit/p-c-kit, p-Akt, p-STAT3, and p-Erk1/2 were detected in vivo and in vitro. The results revealed that XZT significantly reduced ascites weight and increased urine volume and fecal water content in model rats. XZT promoted intestinal motility and increased MTL level but reduced SP and SS levels. It enhanced the current of Na⁺ and K⁺ in ICCs and improved c-kit expression and signaling mediator phosphorylation in SCF/c-kit, which was inhibited by imatinib in vitro and downregulated in model rats in vivo. Our study concluded that XZT reduced the amount of ascites and improved intestinal motility in cirrhotic rats, which may be associated with its effect on ascites and was involved in the mechanisms regulating the SCF/c-kit signaling pathway in ICCs and improving gastrointestinal hormone secretion.

Mesoporous silica nanoparticles (MSNs) feature a high surface area and large pore volume, uniform and tunable pore size, and stable framework; thus, they have been used extensively as drug carriers. The synthesis, classification, and the latest generation of MSNs, drug loading methods, modification of MSNs, pharmacokinetic studies, biocompatibility, and toxicity of MSNs, and their application in drug delivery systems (DDS) are covered in this review. It is crucial to uncover the mechanism for the formation of MSNs. Before drug loading, the characteristics of MSNs should be taken into consideration. In addition, the porosity, particle size and morphology, surface oxidation and surface functionalization can also influence the in vivo fate of MSNs, which is worthy of further study. Coating MSNs with novel materials may improve their biocompatibility, control the release of drugs loaded into the MSNs or enhance the uptake of the coated MSNs by tumor cells. MSNs can also be used as carriers for combination therapy in the treatment of cancer. Despite the rapid development of MSNs, the biological effects of these biomaterials remain relatively less understood.

Background: Psoriasis is a common chronic inflammatory skin disease. Its treatment is challenged by the limited amount of drug reaching the inflamed skin. The overexpressed CD44 protein in inflamed psoriatic skin can serve as a potential target of novel active-targeting nanocarriers to increase drug accumulation in the skin.