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The tissue-specific targeted delivery and efficient cellular uptake of siRNAs are the main obstacles to their clinical application. Antibody-siRNA-conjugates (ARCs) can deliver siRNA by exploiting the targeting property of antibodies like antibody-drug conjugates (ADCs). However, the effective conjugation of antibodies and siRNAs and the release of siRNAs specifically at target sites have posed challenges to the development of ARCs. In this study, the successful conjugation of antibodies and siRNAs was achieved using a multifunctional peptide as a linker, composed of a cell-penetrating peptide (CPP) and a substrate peptide (SP), which is highly expressed in solid tumors. The resulting antibody-multifunctional peptide (SP-CPP)-siRNA system delivered the siRNA to target tumor cells by the specific binding of the antibody. Once the enzymes on the tumor cell surface hydrolyzed the substrate peptide linker, siRNA-CPP was released from ARCs. The released siRNA-CPP entered the targeted cells via the cellular penetrating ability of CPP, resulting in improved siRNA-mediated gene silencing efficiency, verified both in vitro and in vivo. After intravenous administration, the designed ARCs achieved approximately 66.7% EGFP (Enhanced Green Fluorescent Protein) downregulation efficiency in nude mice xenografted with the HCT116-EGFP tumor model. The proposed system provides a prospective choice for ARC production and the safe and efficient delivery of siRNAs.

Objective Uncoupling protein 3 gene (UCP3) is a candidate gene associated with the meat quality of pigs. The aim of this study was to explore the regulation mechanism of UCP3 expression and provide a theoretical basis for the research of the function of porcine UCP3 gene in meat quality. Methods Bisulfite sequencing polymerase chain reaction (PCR) and quantitative real-time PCR (Q-PCR) were used to analyze the methylation of UCP3 5'-flanking region and UCP3 mRNA expression in the adipose tissue or skeletal muscle of three pig breeds at different ages (1, 90, 210-day-old Putian Black pig; 90-day-old Duroc; and 90-day-old Dupu). Results Results showed that two cytosine-guanine dinucleotide (CpG) islands are present in the promoter region of porcine UCP3 gene. The second CpG island located in the core promoter region contained 9 CpG sites. The methylation level of CpG island 2 was lower in the adipose tissue and skeletal muscle of 90-day-old Putian Black pigs compared with 1-day-old and 210-day-old Putian Black pigs, and the difference also existed in the skeletal muscle among the three 90-day-old pig breeds. Furthermore, the obvious changing difference of UCP3 mRNA expression was observed in the skeletal muscle of different groups. However, the difference of methylation status and expression level of UCP3 gene was not significant in the adipose tissue. Conclusion Our data indicate that UCP3 mRNA expression level was associated with the methylation status of UCP3 promoter in the skeletal muscle of pigs.

Pancreatic ductal adenocarcinoma (PDAC) is a dominantly (~95%) KRAS-mutant cancer that has extremely poor prognosis, in part this is due to its strong intrinsic resistance towards almost all therapeutic agents. PDAC relies heavily on KRAS-transformed metabolism, including enhanced macropinocytosis and catabolism of extracellular albumin, to maintain its proliferation and progression. However, it has yet to be validated that whether such transformed metabolism could be exploited for the drug delivery to open therapeutic windows of cytotoxic agents in KRAS-mutant PDAC. In this study, we attempt to answer this question by focusing on the impact of two critical regulators of albumin catabolism, KRAS and the neonatal Fc receptor (FcRn), on the sensitivity of PDAC to doxorubicin (DOX, a model cytotoxic agent) and albumin-conjugated doxorubicin (DOX-ALB). Using cell lines and cell-derived xenografts with different KRAS genotypes and FcRn levels, we demonstrated that KRAS-enhanced macropinocytosis and reduced FcRn expression sensitize PDAC to DOX-ALB but not free DOX. In both in vitro and in vivo comparsion, the DOX-ALB demonstrated ~10 times enlarged therapeutic window compared with free DOX, in PDAC with KRAS mutation and reduced FcRn level, two events appear to occur simultaneously in the investigated PDAC. In summary, we conclude that albumin conjugation is an exploitable drug delivery strategy that significantly opens the therapeutic windows of otherwise undevelopable anti-cancer agents for KRAS-mutant PDAC therapy, and creates a new landscape for clinical evaluation and future translation of such compounds.

RNAi technology has aroused wide public interest due to its high efficiency and specificity to treat multiple types of diseases. However, the effective delivery of siRNA remains a challenge due to its large molecular weight and strong anionic charge. Considering their remarkable functions in vivo and features that are often desired in drug delivery carriers, biomimetic systems for siRNA delivery become an effective and promising strategy. Based on this, covalent attachment of synthetic cell penetrating peptides (CPP) to siRNA has become of great interest. We developed a monomeric covalent conjugate of low molecular weight protamine (LMWP, a well-established CPP) and siRNA via a cytosol-cleavable disulfide linkage using PEG as a crosslinker. Results showed that the conjugates didn't generate coagulation, and exhibited much better RNAi potency and intracellular delivery compared with the conventional charge-complexed CPP/siRNA aggregates. Three different synthetic and purification methods were compared in order to optimize synthesis efficiency and product yield. The methodology using hetero-bifunctional NHS–PEG–OPSS as a crosslinker to synthesize LMWP–siRNA simplified the synthesis and purification process and produced the highest yield. These results pave the way towards siRNA biomimetic delivery and future clinical translation., Graphical abstract A monomeric covalent conjugate of low molecular weight protamine (LMWP, a well-established CPP) and siRNA were developed via a cytosol-cleavable disulfide linkage using PEG as a crosslinker. Three different synthetic and purification methods were compared and hetero-bifunctional NHS–PEG–OPSS was the optimized crosslinker.fx1

An anticancer drug delivery system consisting of DNA nanoparticles synthesized by rolling circle amplification (RCA) was developed for prostate cancer membrane antigen (PSMA) targeted cancer therapy. The template of RCA was a DNA oligodeoxynucleotide coded with PSMA-targeted aptamer, drug-loading domain, primer binding site and pH-sensitive spacer. Anticancer drug doxorubicin, as the model drug, was loaded into the drug-loading domain (multiple GC-pair sequences) of the DNA nanoparticles by intercalation. Due to the integrated pH-sensitive spacers in the nanoparticles, in an acidic environment, the cumulative release of doxorubicin was far more than the cumulative release of the drug in the normal physiological environment. In cell uptake experiments, treated with doxorubicin loaded DNA nanoparticles, PSMA-positive C4-2 cells could take up more doxorubicin than PSMA-null PC-3 cells. The prepared DNA nanoparticles showed the potential as drug delivery system for PSMA targeting prostate cancer therapy.

Coating supermagnetic iron oxide nanoparticles (SPIOs) with albumin would not only improve their in vivo stability but also improve their drug loading capacity, but current methods are either inefficient or time consuming. Herein, a single step synthesis of bovine serum albumin (BSA)-stabilized SPIOs with high dispersity and stability via a modified co-precipitation method is reported. The benefits of albumin for coating of SPIOs, i.e. its long circulation life, low immunogenicity and drug binding ability to specific binding domains, were all retained in our mildly modified BSA. The BSA-SPIOs thus prepared displayed an excellent T2 contrast enhancing effect and drug loading capacity. Two cytotoxic drugs curcumin and sunitinib, where the former is a drug-resistance depressor and the latter is a tyrosine kinase inhibitor, were further co-loaded into the BSA-SPIOs (denoted SPIO-SC) to achieve combined synergistic therapy. SPIO-SC formulations displayed the most significant tumor inhibition yet least drug-induced toxicity both in vitro and in vivo when compared with free drug formulations. Through in vivo pharmacokinetic analysis, it was demonstrated that SPIO-SC most efficiently delivered the encapsulated drugs to the tumor site, and at the same time maintained the originally designed, optimal ratios of curcumin to sunitinib concentrations at the tumor target and yielded the most optimal synergistic effect and, subsequently, the more effective therapeutic outcomes. The prepared BSA-SPIOs are an extremely promising candidate for both MR imaging and drug delivery as a healthcare material.

Survival of KRAS mutant pancreatic cancer is critically dependent on reprogrammed metabolism including elevated macropinocytosis, autophagy, and lysosomal degradation of proteins. Lysosomal acidification is indispensable to protein catabolism, which makes it an exploitable metabolic target for KRAS mutant pancreatic cancer. Herein we investigated ultra-pH-sensitive micelles (UPSM) with pH-specific buffering of organelle pH and rapid drug release as a promising therapy against pancreatic cancer. UPSM undergo micelle-unimer phase transition at their apparent p Ka, with dramatically increased buffer capacity in a narrow pH range (

Solid-liquid equilibrium data of cefquinome sulfate is important to develop industrial crystallization processes for cefquinome sulfate. The solubilities of cefquinome sulfate in five pure solvents (methanol, ethanol, ethylene glycol, acetic acid and water) from 277.15 to 305.15 K and in a binary acetone-water solvent from 278.15 to 293.15 K were measured at atmospheric pressure. The pure-solvent solubility data was correlated to the modified Apelblat and Van’t Hoff equations whereas the mixed-solvent system data was correlated to the modified Apelblat, Van’t Hoff, CNIBS/R-K and Jouyban- Acree models. It was found that the solubilities of cefquinome sulfate in all tested solvents decreased with the increasing of temperature. In addition, the thermodynamic properties of the dissolution processes, including standard Gibbs free energy, enthalpy and entropy changes, were calculated using the Van’t Hoff equation. It was found that the dissolution of cefquinome sulfate is exothermic.

Because of the unparalleled efficiency and universal utility in treating a variety of disease types, siRNA agents have evolved as the future drug-of-choice. Yet, the inability of the polyanionic siRNA macromolecules to cross the cell membrane remains as the bottleneck of possible clinical applications. With the cell penetrating peptides (CPP) being discovered lately, the most effective tactic to achieve the highest intracellular siRNA delivery deems to be by covalently conjugating the drug to a CPP; for instance, the arginine-rich Tat or low molecular weight protamine (LMWP) peptides. However, construction of such a chemical conjugate has been referred by scientists in this field as the "Holy Grail" challenge due to self-assembly of the cationic CPP and anionic siRNA into insoluble aggregates that are deprived of the biological functions of both compounds. Based on the dynamic motion of PEG, we present herein a concise coupling strategy that is capable of permitting a high-yield synthesis of the cell-permeable, cytosol-dissociable LMWP-siRNA covalent conjugates. Cell culture assessment demonstrates that this chemical conjugate yields by far the most effective intracellular siRNA delivery and its corresponded gene-silencing activities. This work may offer a breakthrough advance towards realizing the clinical potential of all siRNA therapeutics and, presumably, most anionic macromolecular drugs such as anti-sense oligonucleotides, gene compounds, DNA vectors and proteins where conjugation with the CPP encounters with problems of aggregation and precipitation. To this end, the impact of this coupling technique is significant, far-reaching and wide-spread.

For the past 20 years, we have witnessed an unprecedented and, indeed, rather miraculous event of how cell-penetrating peptides (CPPs), the naturally originated penetrating enhancers, help overcome the membrane barrier that has hindered the access of bio-macromolecular compounds such as genes and proteins into cells, thereby denying their clinical potential to become potent anti-cancer drugs. By taking the advantage of the unique cell-translocation property of these short peptides, various payloads of proteins, nucleic acids, or even nanoparticle-based carriers were delivered into all cell types with unparalleled efficiency. However, non-specific CPP-mediated cell penetration into normal tissues can lead to widespread organ distribution of the payloads, thereby reducing the therapeutic efficacy of the drug and at the same time increasing the drug-induced toxic effects. In view of these challenges, we present herein a review of the new designs of CPP-linked vehicles and strategies to achieve highly effective yet less toxic chemotherapy in combating tumor oncology.

Background: The tumor microenvironment in pancreatic cancer is widely known for its abundant stroma and lacking of tumor blood vessels. Many effective therapeutic agents evaluated in vitro failed to show any benefits in vivo due to the inefficient drug delivery into the tumors. Albumin was reported to naturally accumulate in several types of solid tumors including sarcomas, lung cancer, etc. In this study, we systematically investigated the tumor accumulation and penetration of albumin in pancreatic cancer, and evaluated whether albumin could improve the intratumor drug delivery and therapeutic efficacy by albumin-drug complex. Methods: We prepared a red fluorescence dye (6-TMR)-labeled albumin and studied the tumor accumulation and penetration of albumin in both orthotopic xenograft and the genetically engineered KPC mouse model by in vivo fluorescence imaging and confocal microscope. To further investigate the drug delivery capacity of albumin in pancreatic cancer, we used Cisplatin as a model drug and prepared albumin-Cisplatin complex. Organ and intratumor drug distribution of Cisplatin were measured by ICP-MS and LA-ICP-MS imaging, respectively. Results: Albumin-6-TMR showed tumor-selective accumulation in both orthotopic xenograft and KPC tumors, with about 50-fold higher radiant efficiency than that of free 6-TMR in KPC tumors at 12 h. Intriguingly, the confocal results indicated that albumin-6-TMR could penetrate into the interior of tumor tissues and stay for at least 72 h while no obvious fluorescence was seen in free 6-TMR group. The mechanism of albumin accumulation and penetration in pancreatic tumors is still under investigation. Moreover, administration of albumin-Cisplatin complex significantly reduced Vd by nearly 25 times and increased AUC of Cisplatin in plasma by 33 times, and improved the MRT and AUC of Cisplatin in orthotopic xenograft tumors by 10 and 29 times, respectively. The LA-ICP-MS imaging was being used to confirm intratumor penetration and distribution of Cisplatin in KPC tumors. Finally, albumin-Cisplatin complex exhibited reduced systemic toxicity (the maximum tolerated dose was more than 60 mg/kg of Cisplatin, i.v.) and enhanced inhibition of tumor growth in subcutaneous PANC-1 xenograft mouse models. Importantly, albumin-Cisplatin complex prolonged the survival of orthotopic MIA PaCa-2 xenograft mouse models compared with free Cisplatin. Conclusion: In summary, we have shown for the first time that albumin as a drug carrier could improve intratumor drug delivery in both orthotopic xenograft and KPC tumors. And albumin-Cisplatin complex could significantly reduce systemic toxicity and improve therapeutic efficacy of Cisplatin in preclinical pancreatic cancer models. Together, albumin can be a promising drug carrier and provides a new insight into anti-cancer drug delivery in pancreatic cancer. Citation Format: Chao Kong, Junxiao Ye, Zhengsheng Liu, Weijian Kong, Mengnan Sun, Huiqin Liu, Fang Yuan, Feng Qian. Improved intratumor drug delivery and therapeutic efficacy in pancreatic cancer by albumin-Cisplatin complex [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3624.

Successful development of a new drug is prohibitively expensive, and is estimated to cost approximately $100—500 million US dollars for a single clinical drug. Yet, a newly developed drug can only enjoy its patent protection for 18 years, meaning that after this protected time period, any company can manufacture this product and thus the profit generated by this drug entity would reduce dramatically. Most critically, once a drug is being synthesized, its physical, chemical, and biological attributes such as bioavailability and in vivo pharmacokinetics are all completely fixed and cannot be changed. In principal and practice, only the application of an appropriately designed drug delivery system (DDS) is able to overcome such limitations, and yet the cost of developing a novel drug delivery system is less than 10% of that of developing a new drug. Because of these reasons, the new trend in pharmaceutical development has already begun to shift from the single direction of developing new drugs in the past to a combined mode of developing both new drugs and innovative drug delivery systems in this century. Hence, for developing countries with relatively limited financial resources, a smart strategic move would be to focus on the development of new DDS, which has a significantly higher benefit/risk ratio when comparing to the development of a new drug.

Oral insulin delivery has received the most attention in insulin formulations due to its high patient compliance and, more importantly, to its potential to mimic the physiologic insulin secretion seen in non-diabetic individuals. However, oral insulin delivery has two major limitations: the enzymatic barrier that leads to rapid insulin degradation, and the mucosal barrier that limits insulin’s bioavailability. Several approaches have been actively pursued to circumvent the enzyme barrier, with some of them receiving promising results. Yet, thus far there has been no major success in overcoming the mucosal barrier, which is the main cause in undercutting insulin’s oral bioavailability. In this review of our group’s research, an innovative silica-based, mucoadhesive oral insulin formulation with encapsulated-insulin/cell penetrating peptide (CPP) to overcome both enzyme and mucosal barriers is discussed, and the preliminary and convincing results to confirm the plausibility of this oral insulin delivery system are reviewed. In vitro studies demonstrated that the CPPinsulin conjugates could facilitate cellular uptake of insulin while keeping insulin’s biologic functions intact. It was also confirmed that low molecular weight protamine (LMWP) behaves like a CPP peptide, with a cell translocation potency equivalent to that of the widely studied TAT. The mucoadhesive properties of the produced silica-chitosan composites could be controlled by varying both the pH and composition; the composite consisting of chitosan (25 wt-%) and silica (75 wt-%) exhibited the greatest mucoadhesion at gastric pH. Furthermore, drug release from the composite network could also be regulated by altering the chitosan content. Overall, the universal applicability of those technologies could lead to development of a generic platform for oral delivery of many other bioactive compounds, especially for peptide or protein drugs which inevitably encounter the poor bioavailability issues.

With the hope of overcoming the serious side effects, great endeavor has been made in tumor-targeted chemotherapy, and various drug delivery modalities and drug carriers have been made to decrease systemic toxicity caused by chemotherapeutic agents. Scientists from home and abroad focus on the research of targeted microbubbles contrast agent, and the use of the targeted ultrasound microbubble contrast agent can carry gene drugs and so on to the target tissue, as well as mediated tumor cell apoptosis and tumor microvascular thrombosis block, etc., thus plays the role of targeted therapy. Recent studies have elucidated the mechanisms of drug release and absorption, however, much work remains to be done in order to develop a successful and optimal system. In this review, we summarized the continuing efforts in understanding the usage of the ultrasound triggered target microbubbles in cancer therapy, from release mechanism to preparation methods. The latest applications of ultrasound-triggered targeted microbubbles in cancer therapy, especially in gene therapy and antiangiogenic cancer therapy were discussed. Moreover, we concluded that as a new technology, ultrasound-triggered targeted microbubbles used as drug carriers and imaging agents are still energetic and are very likely to be translated into clinic in the near future.

Conventional chemotherapy has little or no specificity for cancer cells, normally resulting in low drug accumulation at the tumor region (inefficacy) and drug-induced severe side effects (toxicity). Nowadays, new strategies have been developed to improve both the targeting ability and cellular drug uptake using active targeting ligands and drug internalization agents, which could recognize and interact with specific receptors overexpressed on tumor cells and then trigger a drug internalization process by transporting the cargos into cells. Among those strategies, enzyme-triggered cell penetrating peptide (CPP)-mediated systems seem to be a feasible approach. The expression level of specific enzymes like proteases, esterases or glycosidases is often higher in tumor cells than in normal tissues, and such concentration gradients can be exploited as a tool for targeted cancer therapy. CPPs are known to be effective in promoting membrane transportation of the drug cargos, rendering a deeper tumor permeation that could further enhance the therapeutic efficacy of the delivered drug. An enzyme-triggered, CPP-mediated system would combine these advantages to yield a system with the enhanced tumor targeting ability and internalization efficiency and so far many systems have been successfully exploited and applied to cancer therapy. In this review, typical enzymes applied in cancer theranostic systems were firstly reviewed, followed by analyzing pros and cons of cell penetrating peptides. Most importantly, different types of applications of enzyme-triggered CPP-mediated systems in tumor imaging were illustrated. Finally, the drug loaded applications, i.e. enzyme-triggered CPP-mediated systems in drug delivery were reviewed.

Traditionally, any drug intended for combating the tumor would distribute profoundly to other organs and tissues as lack of targeting specificity, thus resulting in limited therapeutic effects toward the tumor but severe drug-induced toxic side effects. To prevail over this obstacle of drug-induced systemic toxicity, a novel approach termed "ATTEMPTS" (antibody targeted triggered electrically modified prodrug type strategy) was designed, which directly introduces both of the targeting and prodrug features onto the protein drugs. The ATTEMPTS system is composed of the antibody targeting component consisting of antibodies linked with heparin, and the cell penetrating peptide (CPP) modified drug component. The two components mentioned above self-assembled into a tight complex via the charge to charge interaction between the anionic heparin and cationic CPP. Once accumulated at the targeting site, the CPP modified drug is released from the blockage by a second triggering agent, while remaining inactive in the circulation during tumor targeting thus aborting its effect on normal tissues. We utilized the heparin-induced inhibition on the cell-penetrating activity of CPP to create the prodrug feature, and subsequently the protamine-induced reversal of heparin inhibition to resume cell transduction of the protein drug via the CPP function. Our approach is the first known system to overcome this selectivity issue, enabling CPP-mediated cellular drug delivery to be practically applicable clinically. In this review, we thoroughly discussed the historical and novel progress of the "ATTEMPTS" system.

A variety of methods including penetrating enhancers, enzyme inhibitors, as well as cargo mediated drug delivery have been explored to improve the intolerance of parenteral administrated insulin, but little success has been achieved so far. Under this background, cell penetrating peptides (CPPs), with their ability to enhance transport efficiency of macromolecular drugs have been demonstrated to be able to increase insulin bioavailability (BA) in a number of studies, of which a BA up to 50.7% relative to subcutaneously administered insulin could be achieved by nasal route under optimal conditions. Furthermore, CPPs could be conveniently formulated with insulin, or be grafted onto drug-loaded cargoes to facilitate the cargo mediated insulin delivery. Here we reviewed the recent achievements on CPP-mediated insulin transport, and outlined various CPP-based delivery strategies which are expected to show potential in clinical translation in the future.

Low molecular weight protamine (LMWP) is a peptide fragment produced in our laboratory from enzymatic digestion of native protamine. More than 30 papers studying the properties and applications of LMWP have been published by our group in various journals since its initial discovery in 1999. Results have shown that LMWP could completely neutralize the anticoagulant functions of both heparin and low molecular weight heparin (LMWH), with reduced antigenicity and cross-reactivity toward the mice-derived anti-protamine antibodies. Aside from its potential as a heparin/LMWH antagonist, LMWP also shows the ability to retard insulin adsorption by the formation of an insoluble complex, making it a less toxic long-lasting insulin product than the conventional neutral protamine Hagedorn (NPH) insulin for diabetic control. Importantly, LMWP (Sequence: VSRRRRRRGGRRRR), with 10 arginine residues in its structure, could function as a cell-penetrating peptide (CPP), also termed protein transduction domain (PTD), to achieve effective intracellular protein or gene delivery in clinical practice. In this paper, we present a thorough review of our work related to LMWP, with the aim of providing readers an insight into its potential to be a clinical protamine substitute as well as a non-toxic cell penetrating peptide applicable to achieve intracellular protein and gene delivery.

Red blood cells (RBCs) based drug carrier appears to be the most appealing for protein drugs due to their unmatched biocompatability, biodegradability, and long lifespan in the circulation. Numerous methods for encapsulating protein drugs into RBCs were developed, however, most of them induce partial disruption of the cell membrane, resulting in irreversible alterations in both physical and chemical properties of RBCs. Herein, we introduce a novel method for encapsulating proteins into intact RBCs, which was meditated by a cell penetrating peptide (CPP) developed in our lab-low molecular weight protamine (LMWP). l-asparaginase, one of the primary drugs used in treatment of acute lymphoblastic leukemia (ALL), was chosen as a model protein to illustrate the encapsulation into erythrocytes mediated by CPPs. In addition current treatment of ALL using different l-asparaginase delivery and encapsulation methods as well as their associated problems were also reviewed.

Skin is an attractive target for delivery of genetic therapeutics and vaccines. However, the effective delivery of nucleic acids through the skin is primarily limited by the highly organized structure of the stratum corneum. Herein we propose a novel strategy to overcome the formidable barrier of skin by using the skin-permeable LMWP/PGA/PEI/DNA quaternary nanoparticles (NPs) with a self-assembling layer-by-layer structure. The ternary layer of anionic poly(γ-glutamic acid) (PGA) coats the cationic nano-core of PEI/DNA, and the outermost layer is the cell-penetrating low molecular weight protamine (LMWP) peptide. The LMWP functions as a biological permeation enhancer, promoting not only skin permeation but also cell penetration. Our results showed that the cellular uptake and transfection level were greatly improved by the LMWP-modified quaternary NPs compared with the conventional PEI/DNA NPs, displaying a four-fold increase. Skin penetration of the quaternary NPs was significant, showing the high cumulative amount of percutaneous delivery up to 14% of the applied dose. Importantly, skin penetration efficiency of the quaternary NPs was further enhanced by a synergistic effect of LMWP and the chemical permeation enhancer sodium lauryl sulfate up to 23.8%. The results suggested that the skin-permeable NPs could be a promising approach for percutaneous gene delivery.