Lipid nanoparticles (LNPs) have been commonly used as a vehicle for nucleic acids, such as small interfering RNA (siRNA); the surface modification of LNPs is one of the determinants of their delivery efficiency especially in systemic administration. However, the applications of siRNA-encapsulated LNPs are limited due to a lack effective systems to deliver to solid tumors. Here, we report a smart surface modification using a charge-switchable ethylenediamine-based polycarboxybetaine for enhancing tumor accumulation via interaction with anionic tumorous tissue constituents due to selective switching to cationic charge in response to cancerous acidic pH. Our polycarboxybetaine-modified LNP could enhance cellular uptake in cancerous pH, resulting in facilitated endosomal escape and gene knockdown efficiency. After systemic administration, the polycarboxybetaine-modified LNP accomplished high tumor accumulation in SKOV3-luc and CT 26 subcutaneous tumor models. The siPLK-1-encapsulated LNP thereby accomplished significant tumor growth inhibition. This study demonstrates a promising potential of the pH-responsive polycarboxybetaine as a material for modifying the surface of LNPs for efficient nucleic acid delivery.

A variant in a transcription factor gene, POU4F3, is responsible for autosomal dominant nonsyndromic hereditary hearing loss, DFNA15. To date, 14 variants, including a whole deletion of POU4F3, have been reported to cause HL in various ethnic groups. In the present study, genetic screening for POU4F3 variants was carried out for a large series of Japanese hearing loss (HL) patients to clarify the prevalence and clinical characteristics of DFNA15 in the Japanese population. Massively parallel DNA sequencing of 68 target candidate genes was utilized in 2,549 unrelated Japanese HL patients (probands) to identify genomic variations responsible for HL. The detailed clinical features in patients with POU4F3 variants were collected from medical charts and analyzed. Novel 12 POU4F3 likely pathogenic variants (six missense variants, three frameshift variants, and three nonsense variants) were successfully identified in 15 probands (2.5%) among 602 families exhibiting autosomal dominant HL, whereas no variants were detected in the other 1,947 probands with autosomal recessive or inheritance pattern unknown HL. To obtain the audiovestibular configuration of the patients harboring POU4F3 variants, we collected audiograms and vestibular symptoms of the probands and their affected family members. Audiovestibular phenotypes in a total of 24 individuals from the 15 families possessing variants were characterized by progressive HL, with a large variation in the onset age and severity with or without vestibular symptoms observed. Pure-tone audiograms indicated the most prevalent configuration as mid-frequency HL type followed by high-frequency HL type, with asymmetry observed in approximately 20% of affected individuals. Analysis of the relationship between age and pure-tone average suggested that individuals with truncating variants showed earlier onset and slower progression of HL than did those with non-truncating variants. The present study showed that variants in POU4F3 were a common cause of autosomal dominant HL.

Introduction of ligands into 100 nm scaled hollow capsules has great potential for diagnostic and therapeutic applications in drug delivery systems. Polyethylene glycol-conjugated (PEGylated) polyion complex vesicles (PICsomes) are promising hollow nano-capsules that can survive for long periods in the blood circulation and can be used to deliver water-soluble macromolecules to target tissues. In this study, cyclic RGD (cRGD) peptide, which is specifically recognized by αVβ3 and αvβ5 integrins that are expressed at high levels in the neovascular system, was conjugated onto the distal end of PEG strands on PICsomes for active neovascular targeting. Density-tunable cRGD-conjugation was achieved using PICsomes with definite fraction of end-functionalized PEG, to substitute 20, 40, and 100% of PEG distal end of the PICsomes to cRGD moieties. Compared with control-PICsomes without cRGD, cRGD-PICsomes exhibited increased uptake into human umbilical vein endothelial cells. Intravital confocal laser scanning microscopy revealed that the 40%-cRGD-PICsomes accumulated mainly in the tumor neovasculature and remained in the perivascular region even after 24 h. Furthermore, we prepared superparamagnetic iron oxide (SPIO)-loaded cRGD-PICsomes for magnetic resonance imaging (MRI) and successfully visualized the neovasculature in an orthotopic glioblastoma model, which suggests that SPIO-loaded cRGD-PICsomes might be useful as a MRI contrast reagent for imaging of the tumor microenvironment, including neovascular regions that overexpress αVβ3 integrins.

The enhanced permeability and retention (EPR) effect is fundamental to tumor-targeted drug delivery using nanoparticles. However, recent studies reported heterogeneity of the EPR effect, and companion diagnostics are considered to be key to predicting and optimizing the benefits of the EPR effect. Here, as a new material to simply endow the function of companion diagnostics to nanoparticles, we designed a poly(ethylene glycol) (PEG) derivative conjugated with low molecular fluorescent dye through synthetic substrate linker that can be cleaved in response to MMP-2, which is overexpressed in tumor extracellular matrix. Upon tumor accumulation, the low molecular fluorescent dye is released from the PEG and quickly excreted to urine, thereby reporting its tumor accumulation level as a fluorescent signal in the urine. In this study, this urinary reporter was conjugated with albumin, and the functionalized albumin exhibited efficient accumulation in various tumors. Importantly, the functionalized albumin exhibited significantly higher excretion of the fluorescent dye in the urine in mice with tumors compared with those without tumors. The PEG derivatives proposed in this study may be a promising tool to predict the EPR effect in individual cancer patients.

Boron neutron capture therapy is a promising tumor treatment method, though its wide application has been limited due to the poor tumor selectivity and intracellular delivery of 10B-compounds. Here, block copolymer-boron cluster conjugate based on the clinically used sodium borocaptate (BSH) and poly(ethylene glycol)-b-poly(glutamic acid) copolymer have been developed for effectively penetrating tumor tissues and homogeneously delivering the boron clusters into cancer cells towards safe and efficient boron neutron capture therapy. The PEGylated block copolymer-boron cluster (BSH) conjugate has demonstrated significant higher cellular uptake and tumor accumulation when compared to the non-PEGylated formulations and BSH. Moreover, the enhanced delivery to tumors of the conjugates, as well as their superior intratumoral penetration, which facilitated reaching the intracellular space of most cells in tumors, allowed the effective ablation of tumors after neutron irradiation.

Strategic delivery of IRDye 700DX (photosensitizer) is a key for improving its effect in photodynamic therapy. In this study, we have synthesized IRDye 700DX-conjugated polymers containing multiple cyclic RGD peptides to deliver IRDye 700DX selectively to tumor cells and tumor-associated blood vessels overexpressing αvβ3 integrin. Our polymer has a backbone of hydrophilic poly(ethylene glycol)-poly(L-glutamic acid) block copolymer, and cyclic RGD peptides are conjugated to side chains of the poly(L-glutamic acid) while IRDye 700DX is conjugated to the terminal of poly(ethylene glycol). The polymers exhibited selective accumulation to the target sites in a subcutaneous solid tumor, and the accumulation was augmented with the increased number of cyclic RGD peptides. More importantly, the polymer containing 15 cyclic RGD peptides in one construct revealed preferential accumulation on the tumor-associated blood vessels without compromising penetration to deep portions of the tumor, thereby drastically inhibiting tumor growth upon photoirradiation, while the polymer containing 5 cyclic RGD peptides showed moderate antitumor activity despite efficient accumulation in the tumor with almost homogenous intratumoral distribution. These results suggest that controlling the intratumoral distribution of IRDye 700DX is critical for successful PDT, and our polymer containing multiple cyclic RGD peptides may be a promising carrier for this spatial control.

Recalcitrant head and neck squamous cell carcinoma (HNSCC) usually relapses after therapy due to the enrichment of drug resistant cancer stem-like cells (CSCs). Nanomedicines have shown potential for eradicating both cancer cells and CSCs by effective intratumoral navigation for reaching particular cell populations and controlling drug delivery. The installation of ligands on nanomedicines is an attractive approach for improving the delivery to CSCs within tumors, though the development of CSC-selective ligand-receptor systems has been challenging. Herein, we found that the CSC subpopulation in HNSCC cells overexpresses αvβ5 integrins, which is preferentially expressed in tumor neovasculature and cancer cells, and can be effectively targeted by using cyclic Arg-Gly-Asp (cRGD) peptide. Thus, in this study, we propose installing cRGD peptide on micellar nanomedicines incorporating cisplatin for improving their activity against CSCs and enhancing survival. Both cisplatin-loaded micelles (CDDP/m) and cRGD-installed CDDP/m (cRGD-CDDP/m) were effective against HNSCC SAS-L1-Luc cells in vitro, though cRGD-installed CDDP/m was more potent than CDDP/m against the CSC fraction. In vivo, the cRGD-CDDP/m also showed significant antitumor activity against HNSCC orthotopic tumors, i.e. SAS-L1 and HSC-2. Moreover, cRGD-CDDP/m rapidly accumulated into the lymph node metastasis of SAS-L1 tumors, effectively inhibiting their growth, and prolonging mice survival. These findings indicate cRGD-installed nanomedicines as an advantageous strategy for targeting CSCs in HNSCC, and particularly, cRGD-CDDP/m as a significant therapeutic strategy against regionally advanced HNSCC.

The crucial balance of stability in blood-circulation and tumor-specific delivery has been suggested as one of the challenges for effective bench-to-bedside translation of nanomedicines (NMs). Herein, we developed a supramolecularly enabled tumor-extracellular (Tex) pH-triggered NM that can maintain the micellar structure with the entrapped-drug during systemic circulation and progressively release drug in the tumor by rightly sensing heterogeneous tumor-pH. Desacetylvinblastine hydrazide (DAVBNH), a derivative of potent anticancer drug vinblastine, was conjugated to an aliphatic ketone-functionalized poly(ethylene glycol)-b-poly(amino acid) copolymer and the hydrolytic stability of the derived hydrazone bond was efficiently tailored by exploiting the compartmentalized structure of polymer micelle. We confirmed an effective and safe therapeutic application of Tex pH-sensitive DAVBNH-loaded micelle (Tex-micelle) in orthotopic glioblastoma (GBM) models, extending median survival to 1.4 times in GBM xenograft and 2.6 times in GBM syngeneic model, compared to that of the free DAVBNH. The work presented here offers novel chemical insights into the molecular design of smart NMs correctly sensing Tex-pH via programmed functionalities. The practical engineering strategy based on a clinically relevant NM platform, and the encouraging therapeutic application of Tex-micelle in GBM, one of the most lethal human cancers, thus suggests the potential clinical translation of this system against other types of common cancers, including GBM.

Cancer cells have high iron requirements due to their rapid growth and proliferation. Iron depletion using iron chelators has a potential in cancer treatment. Previous studies have demonstrated that deferoxamine (DFO) specifically chelates Fe(III) and exhibited antitumor activity in clinical studies. However, its poor pharmacokinetics has limited the therapeutic potential and practical application. Although polymeric iron chelators have been developed to increase the blood retention, none of previous studies has demonstrated their potential in iron chelation cancer therapy. Here, we developed polymeric DFO by the covalent conjugation of DFO to poly(ethylene glycol)-poly(aspartic acid) (PEG-PAsp) block copolymers. The polymeric DFO exhibited iron-chelating ability comparable with free DFO, thereby arresting cell cycle and inducing apoptosis and antiproliferative activity. After intravenous administration, the polymeric DFO showed marked increase in blood retention and tumor accumulation in subcutaneous tumor models. Consequently, polymeric DFO showed significant suppression of the tumor growth compared with free DFO. This study reveals the first success of the design of polymeric DFO for enhancing iron chelation cancer therapy.

Cancer stem-like cells (CSCs) treatment is a plausible strategy for enhanced cancer therapy. Here we report a glucose-installed sub-50-nm nanocarrier for the targeted delivery of small interfering RNA (siRNA) to CSCs through selective recognition of the glucose ligand to the glucose transporter 1 (GLUT1) overexpressed on the CSC surface. The siRNA nanocarrier was constructed via a two-step assembling process. First, a glucose-installed poly(ethylene glycol)-block-poly(l-lysine) modified with lipoic acid (LA) at the ω-end (Glu-PEG-PLL-LA) was associated with a single siRNA to form a unimer polyion complex (uPIC). Second, a 20 nm gold nanoparticle (AuNP) was decorated with ~65 uPICs through AuS bonding. The glucose-installed targeted nanoparticles (Glu-NPs) exhibited higher cellular uptake of siRNA payloads in a spheroid breast cancer (MBA-MB-231) cell culture compared with glucose-unconjugated control nanoparticles (MeO-NPs). Notably, the Glu-NPs became more efficiently internalized into the CSC fraction, which was defined by aldehyde dehydrogenase (ALDH) activity assay, than the other fractions, probably due to the higher GLUT1 expression level on the CSCs. The Glu-NPs elicited significantly enhanced gene silencing in a CSC-rich orthotopic MDA-MB-231 tumor tissue following systemic administration to tumor-bearing mice. Ultimately, the repeated administrations of polo-like kinase 1 (PLK1) siRNA-loaded Glu-NPs significantly suppressed the growth of orthotopic MDA-MB-231 tumors. These results demonstrate that Glu-NP is a promising nanocarrier design for CSC-targeted cancer treatment.

For systemic delivery of small interfering RNA (siRNA) to solid tumors, we developed an actively-targeted unimer polyion complex-assembled gold nanoparticle (uPIC-AuNP) by a two-step assembling process. First is the monodispersed uPIC formation from the single molecules of therapeutic siRNA and the block catiomer, cyclic RGD (cRGD) peptide-installed poly(ethylene glycol)-block-poly(l-lysine) modified with lipoic acid (LA) at the ω-end (cRGD-PEG-PLL-LA). Second is the surface decoration of a 20nm-sized AuNP with uPICs. The cRGD-installed uPIC-AuNPs (cRGD-uPIC-AuNP) provided the targetability for selective binding to the cancer and cancer-related endothelial cellular surface, while regulating their size <50nm with a quite narrow distribution. The targeting efficacy of the cRGD-uPIC-AuNP was confirmed by in vitro cellular uptake in cultured cervical cancer (HeLa) cells and in vivo tumor accumulation in a subcutaneous HeLa model after systemic administration, compared with a non-targeted control uPIC-AuNP. Due to the targetability of the ligand, the cRGD-uPIC-AuNP achieved the significantly enhanced gene silencing ability in the subcutaneous HeLa tumor. Ultimately, the systemic delivery of siRNA targeted for papilloma virus-derived E6 oncogene by cRGD-uPIC-AuNP significantly inhibited the growth of subcutaneous HeLa tumor. This research demonstrates that the bottom-up construction of nanocarriers using monodispersed building blocks can be employed as delivery platforms for RNA interference-based cancer therapy.

Treatment of recurrent or advanced cervical cancer is still limited, and new therapeutic choices are needed for improving prognosis and quality of life of patients. Because human papilloma virus (HPV) infection is critical in cervical carcinogenesis, with the E6 and E7 oncogenes of HPV degrading tumor suppressor proteins through the ubiquitin proteasome system, the inhibition of the ubiquitin proteasome system appears to be an ideal target to suppress the growth of cervical tumors. Herein, we focused on the ubiquitin proteasome inhibitor MG132 (carbobenzoxy-Leu-Leu-leucinal) as an anticancer agent against cervical cancer cells, and physically incorporated it into micellar nanomedicines for achieving selective delivery to solid tumors and improving its in vivo efficacy. These MG132-loaded polymeric micelles (MG132/m) showed strong tumor inhibitory in vivo effect against HPV-positive tumors from HeLa and CaSki cells, and even in HPV-negative tumors from C33A cells. Repeated injection of MG132/m showed no significant toxicity to mice under analysis by weight change or histopathology. Moreover, the tumors treated with MG132/m showed higher levels of tumor suppressing proteins, hScrib and p53, as well as apoptotic degree, than tumors treated with free MG132. This enhanced efficacy of MG132/m was attributed to their prolonged circulation in the bloodstream, which allowed their gradual extravasation and penetration within the tumor tissue, as determined by intravital microscopy. These results support the use of MG132 incorporated into polymeric micelles as a safe and effective therapeutic strategy against cervical tumors.

Block copolymer of poly(ethylene glycol)-block-poly{N-[N-(2-aminoethyl)-2-aminoethyl]aspartamide} (PEG-P[Asp(DET)]) has been originally introduced as a promising gene carrier by forming a nanomicelle with plasmid DNA. In this study, the polyplex micelle of PEG-SS-P[Asp(DET)], which disulfide linkage (SS) between PEG and cationic polymer can detach the surrounding PEG chains upon intracellular reduction, was firstly evaluated with respect to in vivo transduction efficiency and toxicity in comparison to that of PEG-P[Asp(DET)] in peritoneally disseminated cancer model. Intraperitoneal (i.p.) administration of PEG-SS-P[Asp(DET)] polyplex micelles showed a higher (P<0.05) transgene expression compared with PEG-P[Asp(DET)] in tumors. In contrast, the delivered distribution of the micelles was not different between the two polyplex micelles. PEG-SS-P[Asp(DET)] micelle encapsulating human tumor necrosis factor α (hTNF-α) gene exhibits a higher antitumor efficacy against disseminated cancer compared with PEG-P[Asp(DET)] or saline control. No hepatic and renal toxicities were observed by the administration of polyplex micelles. In conclusion, PEG-detachable polyplex micelles may represent an advantage in gene transduction in vivo over PEG-undetachable polyplex micelles after i.p. administration for peritoneal dissemination of cancer.

Stabilisation of fragile oligonucleotides, typically small interfering RNA (siRNA), is one of the most critical issues for oligonucleotide therapeutics. Many previous studies encapsulated oligonucleotides into ~100-nm nanoparticles. However, such nanoparticles inevitably accumulate in liver and spleen. Further, some intractable cancers, e.g., tumours in pancreas and brain, have inherent barrier characteristics preventing the penetration of such nanoparticles into tumour microenvironments. Herein, we report an alternative approach to cancer-targeted oligonucleotide delivery using a Y-shaped block catiomer (YBC) with precisely regulated chain length. Notably, the number of positive charges in YBC is adjusted to match that of negative charges in each oligonucleotide strand (i.e., 20). The YBC rendezvouses with a single oligonucleotide in the bloodstream to generate a dynamic ion-pair, termed unit polyion complex (uPIC). Owing to both significant longevity in the bloodstream and appreciably small size (~18 nm), the uPIC efficiently delivers oligonucleotides into pancreatic tumour and brain tumour models, exerting significant antitumour activity.

A major critical issue in systemically administered nanomedicines is nonspecific clearance by the liver sinusoidal endothelium, causing a substantial decrease in the delivery efficiency of nanomedicines into the target tissues. Here, we addressed this issue by in situ stealth coating of liver sinusoids using linear or two-armed poly(ethylene glycol) (PEG)-conjugated oligo(l-lysine) (OligoLys). PEG-OligoLys selectively attached to liver sinusoids for PEG coating, leaving the endothelium of other tissues uncoated and, thus, accessible to the nanomedicines. Furthermore, OligoLys having a two-armed PEG configuration was ultimately cleared from sinusoidal walls to the bile, while OligoLys with linear PEG persisted in the sinusoidal walls, possibly causing prolonged disturbance of liver physiological functions. Such transient and selective stealth coating of liver sinusoids by two-arm-PEG-OligoLys was effective in preventing the sinusoidal clearance of nonviral and viral gene vectors, representatives of synthetic and nature-derived nanomedicines, respectively, thereby boosting their gene transfection efficiency in the target tissues.

We describe the development and application of intravital confocal micro-videography to visualize entrance, distribution, and clearance of drugs within various tissues and organs. We use a Nikon A1R confocal laser scanning microscope system attached to an upright ECLIPSE FN1. The Nikon A1R allows simultaneous four channel acquisition and speed of 30 frames per second while maintaining high resolution of 512 × 512 scanned points. The key techniques of our intravital imaging are (1) to present a flat and perpendicular surface to the objective lens, and (2) to expose the subject with little or no bleeding to facilitate optical access to multiple tissues and organs, and (3) to isolate the subject from the body movement without compressing the blood vessels, and (4) to insert a tail vein catheter for timed injection without moving the subject. Ear lobe dermis tissue was accessible without surgery. Liver, kidney, and subcutaneous tumor were accessed following exteriorization through skin incision. In order to image initial extravasations of compounds into tissue following intravenous injection, movie acquisition was initialized prior to drug administration. Our technique can serve as a powerful tool for investigating biological mechanisms and functions of intravenously injected drugs, with both spatial and temporal resolution.

Hypoxia-inducible factor-1 (HIF-1) plays a central role in cellular response to hypoxia by activating vascular endothelial growth factor (VEGF) and other angiogenic factors. Prolyl hydroxylase domain-2 (PHD2) protein induces the degradation of HIF-1 by hydroxylating specific prolyl residues. Therefore gene silencing of PHD2 by RNA interference (RNAi) might increase the expression of angiogenic growth factors and, consequently, neoangiogenesis through the stabilization of HIF-1alpha. In this study we have shown that the specific silencing of PHD2 is sufficient for stabilizing HIF-1alpha and increasing its transcriptional activity, resulting in the increased expression of angiogenic factors including VEGF and fibroblast growth factor-2 (FGF2). Moreover, when PHD2-siRNA vector was used, the increase in VEGF secretion was observed for as long as 18 days after transfection. In vitro treatment of human umbilical vein endothelical cells with conditioned medium from PHD2-siRNA vector-transfected NIH3T3 cells was shown to increase cell proliferation. Also, in vivo angiogenesis was observed in mice implanted with Matrigel plugs mixed with NIH3T3 cells transfected with PHD2-siRNA vector. These results indicate that PHD2 silencing induces expressions of multiple angiogenic growth factors by stabilizing HIF-1alpha, and that the implantation of cells transfected with PHD2-siRNA vector is sufficient to enhance angiogenesis in vivo. In the light of these findings, PHD2 silencing by RNAi might offer a potential tool for angiogenic therapy.

In regard to gene vectors for cancer gene therapy, their percolation into the tumor tissue should be essential for successful outcome. Here, we studied the tumor penetrability of nonviral vectors (polyplexes) after incubation with the multicellular tumor spheroid (MCTS) models and intratumoral (i.t.) injection into subcutaneous tumors. As a result, polyethylene glycolated (PEGylated), core-shell type polyplexes (polyplex micelles) showed facilitated percolation and improved transfection inside the tumor tissue, whereas conventional polyplexes from cationic polymers exhibited limited percolation and localized transfection. Furthermore, the transfection of hypoxia-responsive plasmid demonstrated that polyplex micelles allowed the transfection to the hypoxic region of the tumor tissue in both in vitro and in vivo experiments. To the best of our knowledge, our results demonstrated for the first time that polyplex micelles might show improved tumor penetrability over cationic polyplexes, thereby achieving transfection into the inside of the tumor tissue.

In photodynamic therapy (PDT), the inherent physicochemical properties of a photosensitizer (PS) critically affect its biodistribution and therapeutic outcome as well as side effect. Here, we developed a PS-polymer conjugate displaying isothermal hydrophilic-to-hydrophobic phase transition in response to tumorous acidic pH. The polymer backbone was poly(N-isopropylacrylamide (NIPAAm)/2-aminoisoprpylacrylamide (AIPAAm)) (P(NIPAAm/AIPAAm)), which shows lower critical solution temperature (LCST) of 30 °C. The amine groups in its side chains were converted to hydrophilic acid-labile 2-propionic-3-methylmaleic (PMM) amides, forming poly(NIPAAm/AIPAAm-PMM). The conjugation of PMM moieties drastically increased the LCST of the polymer to 40 °C and displayed hydrophilic character to minimalize unspecific interaction of PS-P(NIPAAm/AIPAAm-PMM) in bloodstream, diminishing potential photosensitivity. The detachment of PMM at tumorous pH lowered the LCST to that of original P(NIPAAm/AIPAAm), permitting hydrophilic-to-hydrophobic transition at a physiological temperature (37 °C). This pH-responsive isothermal phase transition facilitated interaction with the cultured cancer cells, accomplishing 8.1 times-enhanced cellular uptake and strong phototoxicity in a tumorous pH-selective manner. Even in subcutaneous tumor models, our polymer conjugates exhibited efficient tumor accumulation and significantly augmented PDT effect without inducing unfavorable photochemical toxicity to the skin. This study offers a novel concept of PS delivery systems targeting tumorous pH by the use of isothermal phase transition.

Genome editing using CRISPR/Cas9 has attracted considerable attention for the treatment of genetic disorders and viral infections. Co-delivery of Cas9 mRNA and single guide (sg)RNA is a promising strategy to efficiently edit the genome of various cell types, including non-dividing cells, with minimal safety concerns. However, co-delivery of two RNA species with significantly different sizes, such as Cas9 mRNA (4.5 kb) and sgRNA (0.1 kb), is still challenging, especially in vivo. Here, we addressed this issue by using a PEGylated polyplex micelle (PM) condensing the RNA in its core. PM loading sgRNA alone released sgRNA at minimal dilution in buffer, while PM loading Cas9 mRNA alone was stable even at higher dilutions. Interestingly, co-encapsulating sgRNA with Cas9 mRNA in a single PM prevented sgRNA release upon dilution, which led to the enhanced tolerability of sgRNA against enzymatic degradation. Subsequently, PM with co-encapsulated RNA widely induced genome editing in parenchymal cells in the mouse brain, including neurons, astrocytes, and microglia, following intraparenchymal injection, at higher efficiency than that by co-delivery of PMs loaded with either Cas9 mRNA or sgRNA separately. To the best of our knowledge, this is the first report demonstrating the utility of RNA-based delivery of CRISPR/Cas9 in inducing genome editing in the brain parenchymal cells. Furthermore, the efficiency of genome editing using PMs was higher than using a non-PEGylated polyplex, due to the enhanced diffusion of PMs in the brain tissue. The results reported herein demonstrate the potential of using PMs to co-encapsulate Cas9 mRNA and sgRNA for in vivo genome editing.