Selective Accumulation to Tumor Cells with Coacervate Droplets Formed from a Water-Insoluble Acrylate Polymer.

Selective targeting of specific cells without the use of biological ligands has not been achieved. In the present study, we revealed that the coacervate droplets formed from poly(2-methoxyethyl acrylate) (PMEA) and its derivatives selectively accumulated to tumor cells. PMEA derivatives, which are insoluble acrylate polymers, induced coacervation in water to form polymer-dense droplets via hydrophobic interaction. Interestingly, the accumulation of coacervate droplets to tumor cells was involved in the bound water content of PMEA derivatives. Coacervate droplets with a high bound water content accumulated and internalized up to 36.6-fold higher in HeLa cervical tumor cells than in normal human fibroblasts (NHDF). Moreover, the interactions between coacervate droplets and plasma membrane components such as CD44 played a key role in this accumulation process. Therefore, coacervate droplets formed from PMEA derivatives have great clinical potential in tumor cell detection, development of alternative tumor-targeting ligands, and optimization of drug delivery carriers.

Expression Patterns and Levels of All Tubulin Isotypes Analyzed in GFP Knock-In C. elegans Strains.

Most organisms have multiple α- and ß-tubulin isotypes that likely contribute to the diversity of microtubule (MT) functions. To understand the functional differences of tubulin isotypes in Caenorhabditis elegans, which has nine α-tubulin isotypes and six ß-tubulin isotypes, we systematically constructed null mutants and GFP-fusion strains for all tubulin isotypes with the CRISPR/Cas9 system and analyzed their expression patterns and levels in adult hermaphrodites. Four isotypes-α-tubulins TBA-1 and TBA-2 and ß-tubulins TBB-1 and TBB-2-were expressed in virtually all tissues, with a distinct tissue-specific spectrum. Other isotypes were expressed in specific tissues or cell types at significantly lower levels than the broadly expressed isotypes. Four isotypes (TBA-5, TBA-6, TBA-9, and TBB-4) were expressed in different subsets of ciliated sensory neurons, and TBB-4 was inefficiently incorporated into mitotic spindle MTs. Taken together, we propose that MTs in C. elegans are mainly composed of four broadly expressed tubulin isotypes and that incorporation of a small amount of tissue-specific isotypes may contribute to tissue-specific MT properties. These newly constructed strains will be useful for further elucidating the distinct roles of tubulin isotypes.Key words: tubulin isotypes, microtubules, C. elegans.

Carborane as an Alternative Efficient Hydrophobic Tag for Protein Degradation.

Carboranes 1 and 2 were designed and synthesized for hydrophobic tag (HyT)-induced degradation of HaloTag fusion proteins. The levels of the hemagglutinin (HA)-HaloTag2-green fluorescent protein (EGFP) stably expressed in Flp-In 293 cells were significantly reduced by HyT13, HyT55, and carboranes 1 and 2, with expression levels of 49, 79, 43, and 65%, respectively, indicating that carborane is an alternative novel hydrophobic tag (HyT) for protein degradation under an intracellular environment. To clarify the mechanism of HyT-induced proteolysis, bovine serum albumin (BSA) was chosen as an extracellular protein and modified with maleimide-conjugated m-carborane (MIC). The measurement of the ζ-potentials and the lysine residue modification with fluorescein isothiocyanate (FITC) of BSA-MIC conjugates suggested that the conjugation of carborane induced the exposure of lysine residues on BSA, resulting in the degradation via ubiquitin E3 ligase-related proteasome pathways in the cell.

Waterborne diarrhoeal infection risk from multiple water sources and the impact of an earthquake.

In the Kathmandu Valley of Nepal, locals depend on multiple water sources due to the limited access to safe water, which is a great global concern regarding its impact on human health. This study aimed to compare the infection risk of diarrhoea from multiple water sources with different concentrations of Escherichia coli among water supply areas and evaluate the impact of changing water sources due to the Gorkha earthquake on the infection risk. The concentration of enteropathogenic E. coli was estimated in samples of piped water, jar water, groundwater, and tanker water, which were collected in the Valley. The volume of each water ingestion was determined based on a questionnaire survey and considering drinking and bathing sources. The highest estimated risk was observed for households drinking groundwater from shallow dug wells, followed by tanker water. The estimated risk implied the regional disparity due to various water sources with different quality. After the earthquake, the ratio of households drinking only jar water increased, and the estimated risk decreased. The damage on piped water supply, the decrease of tanker water availability and the decrease of residents' trust in groundwater quality presumably enhanced the consumption of jar water despite its high price.

pH-Responsive Coacervate Droplets Formed from Acid-Labile Methylated Polyrotaxanes as an Injectable Protein Carrier.

In prior research it has been demonstrated that methylated ß-cyclodextrins-threaded acid-labile polyrotaxanes (Me-PRXs) exhibit a lower critical solution temperature (LCST) and form coacervate droplets above their LCST. In this study, the encapsulation of proteins in coacervate droplets and the pH-responsive release of proteins, through the acid-induced dissociation of the Me-PRX, were investigated. The coacervate droplets encapsulate various proteins, such as bovine serum albumin (BSA), lysozyme, and ß-galactosidase, at pH 7.4, into their hydrophobic inner phase. Concomitant with the pH-dependent dissociation of the Me-PRXs, the coacervates degraded below pH 6.5 and released encapsulated proteins, with the intrinsic activity of proteins maintained. Additionally, the subcutaneous injection of coacervate droplets encapsulating BSA in mice revealed that the retention time of the BSA at the injection site was prolonged compared to that of free BSA. Altogether, the coacervate droplets of the Me-PRX would be utilized as a new class of pH-responsive and injectable carrier for the controlled release of therapeutic proteins.

Effect of dissolved organic nitrogen contamination on δ15 N-NH4 determination in water samples by modification of the diffusion method with gas-phase trapping.

RATIONALE: The isotopic tracer technique is widely used to identify the sources and fate of nitrogen (N) in order to understand the N cycle and contamination in water environments. The stable isotope ratio of ammonium is expected to greatly enhance the tracing analysis by combining it with the traditional nitrate isotope ratio. Diffusion followed by gas-phase trapping is the most commonly applied method for ammonium isotope ratio measurement. Although dissolved organic nitrogen (DON) is abundant in natural water and its breakdown in the diffusion procedure has been reported, the interference of DON with the measurement of ammonium isotope ratios has not been fully examined. METHODS: This study aims to test the effect of DON contamination by using organic N compounds, viz. humic acid and alanine. A series of diffusion experiments was conducted at a temperature of 80°C for a maximum of 7 days. Ammonia was transferred from alkaline solution and trapped with an acidic filter. This method was applied for samples with ammonium concentrations between 0.5 and 2.0 mg-N/L. RESULTS: There was no difference between the ammonium N stable isotope ratios for samples with and without added DON compounds; the fractionation between the observed value and the actual value was negligible, in the range of 0.2 to 1.0‰. The modifications of previous studies, i.e. shorter diffusion period, no vigorous shaking and using gas-phase trapping, successfully avoided any breakdown of DON in fresh water samples. CONCLUSIONS: The modified method provides high precision and accuracy and it is recommended for the analysis of anthropogenically influenced water samples, such as paddy fields, ground water, rivers and lakes.

Acid-Induced Intracellular Dissociation of ß-Cyclodextrin-Threaded Polyrotaxanes Directed toward Attenuating Phototoxicity of Bisretinoids through Promoting Excretion.

In the retinal pigment epithelium of patients with age-related macular degeneration (AMD), excess N-retinylidene-N-retinylethanolamine (A2E), a dimer of all-trans-retinal, accumulats to induce inflammatory cytokine secretion and phototoxic effects. Therefore, the reduction of intracellular A2E is a promising approach for the prevention and treatment of AMD. In this study, acid-labile ß-cyclodextrin (ß-CD)-threaded polyrotaxanes (PRXs) were synthesized and investigated their effects on the removal of A2E accumulated in retinal pigment epithelium cells (ARPE-19) in comparison to nonlabile PRXs and 2-hydroxypropyl ß-CD (HP-ß-CD) were examined. GC-MS and HPLC studies strongly suggest that the acid-labile PRXs dissociated into their constituent molecules in cells by lysosomal acidification and threaded ß-CDs were considered to be released from the PRXs. The released ß-CDs formed an inclusion complex with A2E, which promoted the excretion of A2E. Indeed, the acid-labile PRXs effectively reduced intracellular A2E level at approximately a 10-fold lower concentration than HP-ß-CD. Accompanied with A2E removal, the toxicity and phototoxicity of A2E were attenuated by treatment with acid-labile PRXs. Because the nonlabile PRX failed to reduce intracellular A2E level and attenuate phototoxicity, intracellular release of threaded ß-CDs from the acid-labile PRX might contribute to reducing intracellular A2E. We conclude that acid-labile PRXs are promising candidates for the treatment of macular diseases through the removal of toxic metabolites.

Lysosomal pH-inducible supramolecular dissociation of polyrotaxanes possessing acid-labile N-triphenylmethyl end groups and their therapeutic potential for Niemann-Pick type C disease.

Niemann-Pick type C (NPC) disease is characterized by the accumulation of cholesterol in lysosomes. We have previously reported that biocleavable polyrotaxanes (PRXs) composed of ß-cyclodextrins (ß-CDs) threaded onto a linear polymer capped with bulky stopper molecules via intracellularly cleavable linkers show remarkable cholesterol reducing effects in NPC disease patient-derived fibroblasts owing to the stimuli-responsive intracellular dissociation of PRXs and subsequent ß-CD release from the PRXs. Herein, we describe a series of novel acid-labile 2-(2-hydroxyethoxy)ethyl group-modified PRXs (HEE-PRXs) bearing terminal N-triphenylmethyl (N-Trt) groups as a cleavable component for the treatment of NPC disease. The N-Trt end groups of the HEE-PRXs underwent acidic pH-induced cleavage and led to the dissociation of their supramolecular structure. A kinetic study revealed that the number of HEE groups on the PRX did not affect the cleavage kinetics of the N-Trt end groups of the HEE-PRXs. The effect of the number of HEE groups of the HEE-PRXs, which was modified to impart water solubility to the PRXs, on cellular internalization efficiency, lysosomal localization efficiency, and cholesterol reduction ability in NPC disease-derived fibroblasts (NPC1 fibroblasts) was also investigated. The cellular uptake and lysosomal localization efficiency were almost equivalent for HEE-PRXs with different numbers of HEE groups. However, the cholesterol reducing ability of the HEE-PRXs in NPC1 fibroblasts was affected by the number of HEE groups, and HEE-PRXs with a high number of HEE groups were unable to reduce lysosomal cholesterol accumulation. This deficiency is most likely due to the cholesterol-solubilizing ability of HEE-modified ß-CDs released from the HEE-PRXs. We conclude that the N-Trt group acts as a cleavable component to induce the lysosomal dissociation of HEE-PRXs, and acid-labile HEE-PRXs with an optimal number of HEE groups (4.1 to 5.4 HEE groups per single ß-CD threaded onto the PRX) have great therapeutic potential for treating NPC disease.

Risk of diarrhoea from shallow groundwater contaminated with enteropathogens in the Kathmandu Valley, Nepal.

Shallow groundwater is the main water source among many alternatives in the Kathmandu Valley, Nepal, which has a rapidly growing population and intermittent piped water supply. Although human pathogens are detected in groundwater, its health effects are unclear. We estimated risk of diarrhoea from shallow groundwater use using quantitative microbial risk assessment. Escherichia coli, Giardia cyst and Cryptosporidium oocyst levels were analysed in dug and tube wells samples. E. coli concentrations were converted to those of enteropathogenic E. coli (EPEC). Risks from EPEC in dug wells and from Cryptosporidium and Giardia in both dug and tube wells were higher than the acceptable limit (<10⁻4 infections/person-year) for both drinking and bathing exposures. Risk from protozoan enteropathogens increased the total risk 10,000 times, indicating that ignoring protozoans could lead to serious risk underestimation. Bathing exposure considerably increased risk, indicating that it is an important pathway. Point-of-use (POU) water treatment decreased the risk six-fold and decreased risk overestimation. Because removal efficiency of POU water treatment has the largest impact on total risk, increasing the coverage and efficiency of POU water treatment could be a practical risk management strategy in the Kathmandu Valley and similar settings.

High-throughput DNA microarray detection of pathogenic bacteria in shallow well groundwater in the Kathmandu Valley, Nepal.

Because of heavy dependence on groundwater for drinking water and other domestic use, microbial contamination of groundwater is a serious problem in the Kathmandu Valley, Nepal. This study investigated comprehensively the occurrence of pathogenic bacteria in shallow well groundwater in the Kathmandu Valley by applying DNA microarray analysis targeting 941 pathogenic bacterial species/groups. Water quality measurements found significant coliform (fecal) contamination in 10 of the 11 investigated groundwater samples and significant nitrogen contamination in some samples. The results of DNA microarray analysis revealed the presence of 1-37 pathogen species/groups, including 1-27 biosafety level 2 ones, in 9 of the 11 groundwater samples. While the detected pathogens included several feces- and animal-related ones, those belonging to Legionella and Arthrobacter, which were considered not to be directly associated with feces, were detected prevalently. This study could provide a rough picture of overall pathogenic bacterial contamination in the Kathmandu Valley, and demonstrated the usefulness of DNA microarray analysis as a comprehensive screening tool of a wide variety of pathogenic bacteria.

Development of a whole community genome amplification-assisted DNA microarray method to detect functional genes involved in the nitrogen cycle.

A novel DNA microarray analysis targeting key functional genes involved in most nitrogen cycling reactions was developed to comprehensively analyze microbial populations associated with the nitrogen cycle. The developed microarray contained 876 oligonucleotide probes based on the nucleotide sequences of the nif, amo, hao/hzo, nap, nar, nirK, nirS, nrf, cnor, qnor and nos genes. An analytical method combining detection by the designed microarray with whole community genome amplification was then applied to monitor the nitrogen cycling microorganisms in river water and wastewater treatment sludge samples. The developed method revealed that nitrogen cycling microorganisms in river water appeared to become less diverse in response to input of effluent from municipal wastewater treatment plants. Additionally, the nitrogen cycling community associated with anaerobic ammonium oxidation and partial nitrification reactors could be reasonably analyzed by the developed method. However, the results obtained for two activated sludge samples from municipal wastewater treatment plants with almost equivalent wastewater treatment performance differed greatly from each other. These results suggested that the developed method is useful for comprehensive analysis of nitrogen cycling microorganisms, although its applicability to complex samples with abundant untargeted populations should be further examined.

Sensitive Detection of Tumor Cells Using Protein Nanoparticles with Multiple Displays of DNA Aptamers and Bioluminescent Reporters.

Simple and effective detection methods for circulating tumor cells are essential for early detection and progression monitoring of tumors. The use of DNA aptamer and bioluminescence is expected to be a key tool for the simple, effective, and sensitive detection of tumor cells. Herein, we designed multifunctional protein nanoparticles for the detection of tumor cells using DNA aptamer and bioluminescence. Fusion proteins (ELP-poly(d)-POIs), composed of elastin-like polypeptide (ELP) fused with protein of interests (POIs) via poly(aspartic acid) (poly(d)), formed the protein nanoparticles based on the temperature responsivity of ELP sequences, leading to multiply displayed POIs on the protein nanoparticles. In the present study, we focused on porcine circovirus type 2 replication initiation protein (Rep), which covalently conjugated with DNA aptamers, and NanoLuc luciferase (Nluc), which emitted a strong bioluminescence, as POIs. ELP-poly(d)-Rep and ELP-poly(d)-Nluc were constructed and formed the protein nanoparticles with multiply displayed Nluc and Rep (DNA aptamer) that amplified the bioluminescence signal and tumor recognition ability. Mucin-1 (MUC1)-overexpressing human breast tumor MCF7 cells and MUC1-recognizing aptamer (MUC1 aptamer) were selected as models. The MUC1 aptamer-conjugated protein nanoparticles exhibited a 13.7-fold higher bioluminescence signal to MCF-7 cells than to human embryonic kidney 293 (HEK293) cells, which express low levels of MUC1. Furthermore, the protein nanoparticles could detect up to 70.7 cells/mL of MCF-7 cells from a cell suspension containing HEK-293. The protein nanoparticles with multiple Rep and Nluc show a great potential as a material for detecting CTCs.

Differences in the Intracellular Localization of Methylated ß-Cyclodextrins-Threaded Polyrotaxanes Lead to Different Cellular States.

Activation of autophagy represents a potential therapeutic strategy for the treatment of diseases that are caused by the accumulation of defective proteins and the formation of abnormal organelles. Methylated ß-cyclodextrins-threaded polyrotaxane (Me-PRX), a supramolecular structured polymer, induces autophagy by interacting with the endoplasmic reticulum. We previously reported on the successful activation of mitochondria-targeted autophagy by delivering Me-RRX to mitochondria using a MITO-Porter, a mitochondria-targeted nanocarrier. The same level of autophagy induction was achieved at one-twentieth the dosage for the MITO-Porter (Me-PRX) compared to the naked Me-PRX. We report herein on the quantitative evaluation of the intracellular organelle localization of both naked Me-PRX and the MITO-Porter (Me-PRX). Mitochondria, endoplasmic reticulum and lysosomes were selected as target organelles because they would be involved in autophagy induction. In addition, organelle injury and cell viability assays were performed. The results showed that the naked Me-PRX and the MITO-Porter (Me-PRX) were localized in different intracellular organelles, and organelle injury was different, depending on the route of administration, indicating that different organelles contribute to autophagy induction. These findings indicate that the organelle to which the autophagy-inducing molecules are delivered plays an important role in the level of induction of autophagy.

Characterization of microbial communities distributed in the groundwater pumped from deep tube wells in the Kathmandu Valley of Nepal.

Although groundwater is a major water supply source in the Kathmandu Valley of Nepal, it is known that the groundwater has significant microbial contamination exceeding the drinking water quality standard recommended by the World Health Organization (WHO), and that this has been implicated in causing a variety of diseases among people living in the valley. However, little is known about the distribution of pathogenic microbes in the groundwater. Here, we analysed the microbial communities of the six water samples from deep tube wells by using the 16S rRNA gene sequences based culture-independent method. The analysis showed that the groundwater has been contaminated with various types of opportunistic microbes in addition to fecal microbes. Particularly, the clonal sequences related to the opportunistic microbes within the genus Acinetobacter were detected in all samples. As many strains of Acinetobacter are known as multi-drug resistant microbes that are currently spreading in the world, we conducted a molecular-based survey for detection of the gene encoding carbapenem-hydrolysing ß-lactamase (bla(oxa-23-like) gene), which is a key enzyme responsible for multi-drug resistance, in the groundwater samples. Nested polymerase chain reaction (PCR) using two specific primer sets for amplifying bla(oxa-23-like) gene indicated that two of six groundwater samples contain multi-drug resistant Acinetobacter.

Modulation of Biological Responses of Tumor Cells Adhered to Poly(2-methoxyethyl acrylate) with Increasing Cell Viability under Serum-Free Conditions.

Circulating tumor cells in body fluids are important biomarkers in cancer diagnosis. The culture of tumor cells isolated from body fluids can provide intrinsic information about tumors and can be used to screen for the best anticancer drugs. However, the culture of primary tumor cells has been hindered by their low viability and difficulties in recapitulating the phenotype of primary tumors in in vitro culture. The culture of tumor cells under serum-free conditions is one of the methodologies to maintain the phenotype and genotype of primary tumors. Poly(2-methoxyethyl acrylate) (PMEA)-coated substrates have been investigated to prolong the proliferation of tumor cells under serum-free conditions. In this study, we investigated the detailed behavior and the mechanism of the increase in tumor cell viability after adherence to PMEA substrates. The blebbing formation of tumor cells on PMEA was attributed not to apoptosis but to the low adhesion strength of cells on PMEA. Moreover, blebbing tumor cells showed amoeboid movement and formed clusters with other cells via N-cadherin, leading to an increase in tumor cell viability. Furthermore, the behaviors of tumor cells adhered to PMEA under serum-free conditions were involved in the activation of the PI3K and Rho-associated protein kinase pathways. Thus, we propose that PMEA would be suitable for the development of devices to cultivate primary tumor cells under serum-free conditions for the label-free diagnosis of cancer.

A ß-hairpin peptide with pH-controlled affinity for tumor cells.

Considering that the pH in the tumor microenvironment is dysregulated, we designed a ß-hairpin peptide (SSRFEWEFESSDPRGDPSSRFEWEFESS). The configuration of the peptide switched from a flexible linear to a rigid loop structure under weakly acidic conditions. The peptide internalized by tumor cells increased significantly under weakly acidic conditions.

Roles of interfacial water states on advanced biomedical material design.

When biomedical materials come into contact with body fluids, the first reaction that occurs on the material surface is hydration; proteins are then adsorbed and denatured on the hydrated material surface. The amount and degree of denaturation of adsorbed proteins affect subsequent cell behavior, including cell adhesion, migration, proliferation, and differentiation. Biomolecules are important for understanding the interactions and biological reactions of biomedical materials to elucidate the role of hydration in biomedical materials and their interaction partners. Analysis of the water states of hydrated materials is complicated and remains controversial; however, knowledge about interfacial water is useful for the design and development of advanced biomaterials. Herein, we summarize recent findings on the hydration of synthetic polymers, supramolecular materials, inorganic materials, proteins, and lipid membranes. Furthermore, we present recent advances in our understanding of the classification of interfacial water and advanced polymer biomaterials, based on the intermediate water concept.

Nanoscopic analyses of cell-adhesive protein adsorption on poly(2-methoxyethyl acrylate) surfaces.

Regulation of protein adsorption on the surface of biomaterials is important for modulating cell adhesion. Two important proteins in this regard are fibrinogen and fibronectin. Poly(2-methoxyethyl acrylate) (PMEA) and its derivatives have been developed as promising coating materials for biomaterial surfaces. Previous studies have highlighted that PMEA-coated substrates suppress thrombogenicity but promote cell adhesiveness. However, it was unclear what was responsible for these differences in adhesion. In this study, we focused on the correlation between protein adsorption and the nanometer-scale structures on the surfaces of the PMEA substrates. An atomic force microscope using protein- or antibody-conjugated cantilevers was used to perform nanoscopic analyses of the adsorption forces and conformational changes in fibrinogen and fibronectin adsorbed on the nanometer-scale PMEA structures. The adsorption force of fibronectin in the polymer-poor region was higher than that of fibrinogen, whereas the polymer-rich region showed a negligible difference in adsorption force between the two proteins. Interestingly, a greater conformational change in the adsorbed fibronectin was induced in the polymer-poor region than that in fibronectin in the polymer-rich region or fibrinogen in either regions, resulting in the induction of cell adhesion. Nanoscopic analyses of protein adsorption on biomaterial surfaces provide promising insights into the design of novel biomaterials that control protein adsorption and cell adhesion.

Relationship between diarrhoea risk and the combinations of drinking water sources in the Kathmandu Valley, Nepal.

In Nepal, the number of diarrhoea hospitalizations in all ages is seriously high. According to the World Health Organization, diarrheal diseases can be substantially prevented through safe drinking water sources. In the Kathmandu Valley, because of the shortage of piped water, local residents use alternative water sources, such as groundwater, jars and tanker water. However, these alternative water sources can be contaminated. This study aimed to clarify the relationship between diarrhoea risk and the combinations of drinking water sources. A survey using multiple questionnaires on diarrhoea occurrence, water sources and water treatment was conducted three time between 2015 and 2016. The odds ratios (ORs) of developing diarrhoea were significantly high for drinking jar (OR 6.1) and tanker water (OR 8.4) compared with not drinking. The combined drinking of jar and tanker water obtained the 1 log higher OR compared with drinking only piped water. Conversely, drinking groundwater had a low OR, implying that the residents refrained from drinking polluted groundwater. In conclusion, diarrhoea occurrence was related not only to the level of water contamination, but also to a behavioural factor, i.e. people's careful management of the choice of multiple water sources.

Cografting of Zwitterionic Sulfobetaines and Cationic Amines on ß-Cyclodextrin-Threaded Polyrotaxanes Facilitates Cellular Association and Tissue Accumulation with High Biocompatibility.

ß-Cyclodextrins (ß-CDs) and ß-CD-containing polymers have attracted considerable attention as potential candidates for the treatment of cholesterol-related metabolic and intractable diseases. We have advocated the use of ß-CD-threaded acid-degradable polyrotaxanes (PRXs) as intracellular delivery carriers for ß-CDs. As unmodified PRXs are insoluble in aqueous solutions, chemical modification of PRXs is an essential process to improve their solubility and impart novel functionalities. In this study, we investigated the effect of the modification of zwitterionic sulfobetaines on PRXs due to their excellent solubility, biocompatibility, and bioinert properties. Sulfobetaine-modified PRXs were synthesized by converting the tertiary amino groups of precursor 2-(N,N-dimethylamino)ethyl carbamate-modified PRXs (DMAE-PRXs) using 1,3-propanesultone. The resulting sulfobetaine-modified PRXs showed high solubility in aqueous solutions and no cytotoxicity, while their intracellular uptake levels were low. To further improve this system, we designed PRXs cografted with zwitterionic sulfobetaine and cationic DMAE groups via partial betainization of the DMAE groups. Consequently, the interaction with proteins, intracellular uptake levels, and liver accumulation of partly betainized PRXs were found to be higher than those of completely betainized PRXs. Additionally, partly betainized PRXs showed no toxicity in vitro or in vivo despite the presence of residual cationic DMAE groups. Furthermore, partly betainized PRXs ameliorated the abnormal free cholesterol accumulation in Niemann-Pick type C disease patient-derived cells at lower concentrations than ß-CD derivatives and previously designed PRXs. Overall, the cografting of sulfobetaines and amines on PRXs is a promising chemical modification for therapeutic applications due to the high cholesterol-reducing ability and biocompatibility of such modified PRXs. In addition, modification with both zwitterionic and cationic groups can be used for the design of various polymeric materials exhibiting both bioinert and bioactive characteristics.