RESUMO
BACKGROUND: A rectal neuroendocrine tumor (rNET) is a malignant tumor originating from neuroendocrine cells. Currently, tumor size is the primary basis for assessing tumor risk. CASE SUMMARY: This article reports the case of a 46-year-old male patient who underwent a colonoscopy that found a 3 mm rectal polypoid bulge. The pathological examination of a sample collected with biopsy forceps revealed a neuroendocrine tumor. Further endoscopic submucosal dissection rescue therapy was used. The presence of lymphatic vessels indicated that the tumor had infiltrated the negative resection margin. The lesion was located in the distal rectum near the anal canal. Therefore, to ensure the patient's quality of life, follow-up observation was conducted after full communication with the patient. No tumor recurrence or distant metastasis has been found during the 13-mo follow-up after surgery. CONCLUSION: Despite the presence of lymphatic invasion and extremely small diameter rNETs in our case, this phenomenon may not imply a higher risk of distant lymph node and organ metastasis.
RESUMO
Low drug encapsulation efficiency and burst release are the main drawbacks of lipid nanoparticles. To solve these problems, lipid nanoparticles containing a cross-linked lipid network were prepared in this study. Monostearin (MS) and octadecylamine (ODA) were used as the solid lipids, and oleic acid (OA) was used as liquid lipid. The use of a small amount of ODA was to form cross-linked network by glutaraldehyde in the presence of OA. Using doxorubicin (DOX) as a model drug, solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC) and glutaraldehyde cross-linked NLC were prepared. The physicochemical properties of these lipid nanoparticles such as average diameter, drug loading, drug encapsulation efficiency and in vitro drug release were investigated. The drug loading capacities and encapsulation efficiency were improved by mixing OA with the solid lipids to produce the nanoparticle matrix, and were further increased by the cross-linking of glutaraldehyde. The faster drug release was obtained when the NLC with higher OA content. After cross-linking by glutaraldehyde, the burst release of DOX from NLC could be reduced, in comparison to both SLN and non cross-linked NLC. The results indicated the NLC with cross-linked network are a potential drug delivery system with improved drug encapsulation and controlled drug release.