To search for nano-drug preparations with high efficiency in tumor treatment, we evaluated the drug-loading capacity and cell-uptake toxicity of three kinds of nanoparticles (NPs). Pullulan was grafted with ethylenediamine and hydrophobic groups to form hydrophobic cholesterol-modified amino-pullulan (CHAP) conjugates. Fourier transform infrared spectroscopy and nuclear magnetic resonance were used to identify the CHAP structure and calculate the degree of substitution of the cholesterol group. We compared three types of NPs with close cholesterol hydrophobic properties: CHAP, cholesterol-modified pullulan (CHP), and cholesterol-modified carboxylethylpullulan (CHCP), with the degree of substitution of cholesterol of 2.92%, 3.11%, and 3.46%, respectively. As compared with the two other NPs, CHAP NPs were larger, 263.9 nm, and had a positive surface charge of 7.22 mV by dynamic light-scattering measurement. CHAP NPs showed low drug-loading capacity, 12.3%, and encapsulation efficiency of 70.8%, which depended on NP hydrophobicity and was affected by surface charge. The drug release amounts of all NPs increased in the acid media, with CHAP NPs showing drug-release sensitivity with acid change. Cytotoxicity of HeLa cells was highest with mitoxantrone-loaded CHAP NPs on MTT assay. CHAP NPs may have potential as a high-efficiency drug carrier for tumor treatment.

Most free drugs that cross the blood–brain barrier are characterized by high liposolubility, but they often have limited clinical applications because of poor dissolution and poor bioavailability. In this study, we prepared donepezil drug-loaded nanoparticles (DZP) with cholesterol-modified pullulan (CHP) as the nanocarrier (DZP-CHP) and surface modified the drug-loaded nanoparticles to improve the water solubility of donepezil while enhancing its targeting and sustained release. We determined the drug loading and encapsulation efficiency of DZP-CHP nanoparticles at different feed ratios. The mean ± SD drug loading and entrapment efficiency were high: 13.52 ± 2.03 and 86.54 ± 1.31. On dynamic light-scattering measurement, mean ± SD particle size was 260.7 ± 1.76 nm, polydispersity index 0.123 ± 0.004, and zeta potential −5.75 ± 0.64 mV. DZP-CHP nanoparticles prepared with the optimal feed ratio (DZP : CHP = 1 : 5) were coated with polysorbate 80, and the adsorption process was determined by isothermal titration calorimetry. We found good affinity between polysorbate 80 and DZP-CHP, with mean ± SD coverage 2.7 ± 0.372. The mean ± SD drug loading and entrapment efficiency of polysorbate 80-emulsified DZP-CHP nanoparticles were 8.25 ± 1.80 and 91.28 ± 4.57, respectively, and the proportion of drug released by 72 h was 42.71%. Compared to DZP-CHP alone, PS-DZP-CHP can enhance the release of donepezil.

Glioma is one of the most common malignant tumors affecting the central nervous system. We screened active drugs from 12 classes to provide experimental data for the study of human glioma. Serum-free suspension clone formation was used to induce the formation of glioma stem‑like cells (GSLCs) from U251 cells. We screened active drugs from 12 classes and observed their effects on the number of tumor balls. The results revealed that serum‑free suspension clone formation successfully induced the formation of GSLCs. Six active drugs [curcumin, chrysin, apigenin, luteolin, casticin and 8-bromo-7-methoxychrysin (BrMChR)] were identified by MTT assay. The drugs that affected the number of tumor balls were curcumin, luteolin, casticin and BrMChR (all P<0.05). The GSLCs were obtained by serum‑free clone suspension formation and exhibited the features of cancer stem cells.

Most Alzheimer’s disease drugs do not work efficiently because of the blood–brain barrier. Therefore, we designed a new nanopreparation (PS-DZP-CHP): cholesterol-modified pullulan (CHP) nanoparticle with polysorbate 80(PS) surface coverage, as donepezil (DZP) carrier to realize brain tissue delivery. By size analysis and isothermal titration calorimetry, we chose the optimal dosing ratio of the drug with nanomaterials (1:5) and designed a series of experiments to verify the efficacy of the nanoparticles. The results of in vitro release experiments showed that the nanoparticles can achieve continuous drug release within 72 h. The results of fluorescence observation in mice showed a good brain targeting of PS-DZP-CHP nanoparticles. Furthermore, the nanoparticle can enhance the drug in the brain tissue concentration in mice. DZP-CHP nanoparticles were used to pretreat nerve cells with Aβ protein damage. The concentration of lactate dehydrogenase was determined by MTT, rhodamine 123 and AO-EB staining, which proved that DZP-CHP nanoparticles had a protective effect on the neurotoxicity induced by Aβ_25–35 and were superior to free donepezil. Microthermal perpetual motion meter test showed that PS-DZP-CHP nanoparticles have an affinity with apolipoprotein E, which may be vital for this nanoparticle targeting to brain tissue.