Efficient Cell Penetration Research Articles

A novel polyhedral oligomeric silsesquioxane nanohybrid fluorescent sensor designed based on an osmotic mechanism for specific detection and intelligent scavenging of magnesium ions

BackgroundMg2+ has long been recognized as one of the most vital cations due to its diverse physiological and pathological roles, making it indispensable in both biomedical and biological research. Organic fluorescent sensors are commonly employed for Mg2+ detection, but they often lack high selectivity and exhibit poor hydrophilicity, limiting their biomedical applications. ResultsHerein, we introduced a novel organic-inorganic hybrid fluorescence sensor, PFHBS, constructed on the POSS nanoplatforms. The efficient connection between PEGylated POSS and the small molecule sensor FHBS through Click chemistry enhances the selectivity and reduces interference, making this chemical sensor ideal for the accurate detection of Mg2+. Furthermore, the incorporation of POSS amplifies the ligand field effect of FHBS, making it more conducive to Mg2+ capture. The modification of PEG chains enhances the sensor's amphiphilicity, facilitating efficient cell penetration and effective Mg2+ detection at the biological level. SignificanceFinally, relying on spontaneous permeation, coupled with its strong ligand field effect and excellent cell permeability, the chemosensor demonstrates the capability to intelligently remove excess Mg2+ from the body. It has been successfully applied to mitigate renal overload resulting from acute Mg2+ poisoning.

Hydrophobic modification improves the delivery of cell-penetrating peptides to eliminate intracellular pathogens in animals.

Infections induced by intracellular pathogens are difficult to eradicate due to poor penetration of antimicrobials into cell membranes. It is of great importance to develop a new generation of antibacterial agents with dual functions of efficient cell penetration and bacterial inhibition. In this study, the association between hydrophobicity and cell-penetrating peptide delivery efficiency was investigated by fragment interception and hydrophobicity modification of natural porcine antimicrobial peptide PR-39 and the combination of cationic cell-penetrating peptide (R6) with antimicrobial peptide fragments modified with hydrophobic residues. The chimeric peptides P3I7 and P3L7, obtained through biofunctional screening, exhibited potent broad-spectrum antibacterial activity and low cytotoxicity. Moreover, P3I7 and P3L7 can effectively penetrate cells to eliminate intracellular pathogens mainly through endocytosis. The membrane destruction mechanism makes the peptides fast sterilizers and less prone to developing drug resistance. Finally, their good biocompatibility and antibacterial infection effects were verified in mice and piglets. To conclude, the chimeric peptides P3I7 and P3L7 show great potential as affordable and effective antimicrobial agents and may serve as ideal candidates for the treatment of intracellular bacterial infections. STATEMENT OF SIGNIFICANCE: The low permeability of antibacterial drugs makes infections induced by intracellular bacteria extremely difficult to treat. To address this issue, we designed chimeric peptides with dual cell-penetrating and antibacterial functions. The active peptides P3I7 and P3L7, acquired through functional screening have strong broad-spectrum antibacterial activity and powerful bactericidal effects against intracellular Staphylococcus aureus. The membrane permeation mechanism of P3I7 and P3L7 against bacteria endows fast bactericidal activity with low drug resistance. The biosafety and antibacterial activity of P3I7 and P3L7 were also validated by in vivo trials. This study provides an ideal drug candidate against intracellular bacterial infections.

Maximizing the recovery of the native p28 bacterial peptide with improved activity and maintained solubility and stability in Escherichia coli BL21 (DE3)

p28 is a natural bacterial product, which recently has attracted much attention as an efficient cell penetrating peptide (CPP) and a promising anticancer agent. Considering the interesting biological qualities of p28, maximizing its expression appears to be a prominent priority. The optimization of such bioprocesses might be facilitated by utilizing statistical approaches such as Design of Experiment (DoE). In this study, we aimed to maximize the expression of “biologically active” p28 in Escherichia coli BL21 (DE3) host by harnessing statistical tools and experimental methods. Using Minitab, Plackett-Burman and Box-Behnken Response Surface Methodology (RSM) designs were generated to optimize the conditions for the expression of p28. Each condition was experimentally investigated by assessing the biological activity of the purified p28 in the MCF-7 breast cancer cell line. Seven independent variables were investigated, and three of them including ethanol concentration, OD600 of the culture at the time of induction, and the post-induction temperature were demonstrated to significantly affect the p28 expression in E. coli. The cytotoxicity, penetration efficiency, and total process time were measured as dependent variables. The optimized expression conditions were validated experimentally, and the final products were investigated in terms of expression yield, solubility, and stability in vitro. Following the optimization, an 8-fold increase of the concentration of p28 expression was observed. In this study, we suggest an optimized combination of effective factors to produce soluble p28 in the E. coli host, a protocol that results in the production of a significantly high amount of the biologically active peptide with retained solubility and stability.

Legumain/pH dual-responsive lytic peptide–paclitaxel conjugate for synergistic cancer therapy

After molecule targeted drug, monoclonal antibody and antibody–drug conjugates (ADCs), peptide–drug conjugates (PDCs) have become the next generation targeted anti-tumor drugs due to its properties of low molecule weight, efficient cell penetration, low immunogenicity, good pharmacokinetic and large-scale synthesis by solid phase synthesis. Herein, we present a lytic peptide PTP7-drug paclitaxel conjugate assembling nanoparticles (named PPP) that can sequentially respond to dual stimuli in the tumor microenvironment, which was designed for passive tumor-targeted delivery and on-demand release of a tumor lytic peptide (PTP-7) as well as a chemotherapeutic agent of paclitaxel (PTX). To achieve this, tumor lytic peptide PTP-7 was connected with polyethylene glycol by a peptide substrate of legumain to serve as hydrophobic segments of nanoparticles to protect the peptide from enzymatic degradation. After that, PTX was connected to the amino group of the polypeptide side chain through an acid-responsive chemical bond (2-propionic-3-methylmaleic anhydride, CDM). Therefore, the nanoparticle (PPP) collapsed when it encountered the weakly acidic tumor microenvironment where PTX molecules fell off, and further triggered the cleavage of the peptide substrate by legumain that is highly expressed in tumor stroma and tumor cell surface. Moreover, PPP presents improved stability, improved drug solubility, prolonged blood circulation and significant inhibition ability on tumor growth, which gives a reasonable strategy to accurately deliver small molecule drugs and active peptides simultaneously to tumor sites.

Photo-induced telomeric DNA damage in human cancer cells.

Herein we report on the study of novel dinuclear ruthenium(ii) complexes designed to target and to photo-react with G-quadruplex telomeric DNA. Upon irradiation, complexes efficiently generate guanine radical cation sites as photo-oxidation products. The compounds also display efficient cell penetration with localization to the nucleus and show strong photocytotoxicity toward osteosarcoma cells. Thanks to a microscopic-based telomere dysfunction assay, which allows the direct visualization of DNA damage in cells, we brought the first evidence of forming photo-oxidative damage at telomeres in cellulo. This emphasizes interesting prospects for the development of future cancer phototherapies.

Synthesis and structure‐activity relationship of mitochondria‐targeting peptoids with varying hydrophobicity and cationic charge

AbstractMitochondria‐targeted delivery methods offer a straightforward approach for studying mitochondria‐related diseases and potentially streamlining therapeutic development. Peptoids (oligo‐N‐substituted glycines) are biocompatible peptidomimetics that display similar physicochemical properties as peptides with the added advantage of enhanced resistance to proteolytic cleavage. In particular, amphipathic peptoids are membrane‐permeable and their cationic charges and hydrophobicity can be readily modified for specific purposes, such as cell penetration, anti‐cancer or antibacterial activity. Previously, we identified a series of amphipathic peptoids that showed efficient cell penetration and mitochondrial localization. As a continued effort to identify selective mitochondrial transporters, we designed new analogs with varying hydrophobicity and net charges. We observed that overall increase in hydrophobicity did not result in enhanced mitochondrial localization while maintaining high cell permeability. Moreover, a certain degree of a positive net charge was critical for mitochondrial localization. In conclusion, our mitochondria‐targeting peptoids provide a highly selective and robust delivery system for bioactive molecules.

Cell-Penetrating Peptide and α-Tocopherol-Conjugated Poly(amidoamine) Dendrimers for Improved Delivery and Anticancer Activity of Loaded Paclitaxel.

Even though existing chemotherapeutic agents, including paclitaxel (PTX), possess superior anticancer activity, their application is limited because of extreme hydrophobicity. Here, a dendrimer-based nanoparticles system has been prepared for improved delivery of loaded paclitaxel to the tumor. The cell-penetrating peptides, octa-arginine (R) and vitamin-E succinate (VES), had been conjugated to the PEGylated generation 4 polyamidoamine dendrimer (D) to form RVES-PD. The synthesized polymers had been characterized by 1NMR, IR, and gel permeation chromatography. The PTX-loaded RVES-PD (RVES-PD-PTX) was physicochemically characterized for particle size, zeta potential analysis, drug loading, release, and encapsulation studies. Cellular uptake, cytotoxicity, and apoptosis determination studies were carried out in human lung cancer cells (A549) in monolayers and spheroids. In vivo antitumor efficacy of RVES-PD-PTX was determined using B16F10 tumor-bearing mice. The results indicated that the RVES-PD nanoparticles were taken up by cancer cells effectively and demonstrated improved cellular translocation compared to nontargeted VES-PD. The cytotoxicity study revealed that RVES-PD-PTX exhibited the highest cytotoxicity of PTX compared to nontargeted VES-PD-PTX and free PTX in the PTX concentration range of 0-50 μg/mL. RVES-PD-PTX-induced apoptosis as analyzed by the Annexin V assay and suppressed the growth of spheroids to the highest extent compared to VES-PD-PTX and free PTX. Furthermore, the biodistribution study indicated that the RVES-PD had higher accumulation in tumor compared to VES-PD. The in vivo experiment using B16F10 tumor-bearing mice demonstrated that the RVES-PD treatment resulted in the highest rate of tumor volume reduction and apoptosis primarily by upregulating caspase 3/7 to the highest extent compared to VES-PD and free PTX. In conclusion, the developed RVES-PD could load PTX and showed efficient cell penetration and improved PTX-mediated cytotoxicity in all tested in vitro and in vivo assay systems. The results strongly suggest further exploration of this developed PTX-nanoformulation in cancer treatment.

Development of Cell-Penetration PG-Surfactants and Its Application in External Peptide Delivery to Cytosol.

Recently, development of techniques to deliver pharmacologically active biomacromolecules such as peptides and proteins to cytosol has gained much interest. Here, we applied the peptide gemini (PG)-surfactants to a novel platform to design cell penetration lipopeptides (CP-PGs), which can deliver exogenous peptides and proteins to cytosol. Among the number of candidate CP-PGs having different peptide sequences at the X-, Y-, and Z-positions, we focused on those having two C12 alkyl chains appended to the side chain of two Cys residues, the betaine sequence -Asp-Lys-Asp-Lys- between the alkylated Cys residues (i.e., at the X-position), and having different cationic peptide sequences of oligo-Lys or oligo-Arg at the Y- and/or Z-positions. With respect to cytotoxicity for mammalian cells such as NIH3T3 cells upon 1 h exposure, those having (Lys)3 (K3-DKDKC12 and DKCK12-K3) showed lower cytotoxicity (IC50 = 241 and 198 μM) among those having oligo-Lys, (Lys)n (n = 1, 3, 5; IC50 = 88-197 μM). Similar lower cytotoxicity was also observed for the CP-PG having two (Lys)3 at both N- and C-terminal sides (K3-DKDKC12-K3) (IC50 = 225 μM). In contrast, the CP-PG having (Arg)3 at the N-terminal side (R3-DKDKC12) showed higher cytotoxicity (IC50 = 88 μM). Carrier abilities of the CP-PGs for exogenous peptides were evaluated using the proapoptotic domain (PAD) peptide, which induces apoptosis by disturbing mitochondrial membranes after delivery into cytosol. As a result, the CP-PGs of K3-DKDKC12, DKCK12-K3, K3-DKDKC12-K3, DKCK12-K5, and R3-DKDKC12 exhibited micromolar range carrier ability (the necessary half concentration to induce cell death (EC50) by delivering PAD peptide to cytosol was 10, 6.2, 8.5, 5.8, and 11.5 μM, respectively). Especially, the carrier abilities of DKCK12-K3 and DKCK12-K5 were superior to the well-established cell penetration Arg-rich R8 peptide (EC50 = 6.8 μM). Together, our results indicate that the PG-surfactant molecular framework could be a potential new platform to design efficient cell penetration carrier materials.

Intracellular delivery of therapeutic antibodies into specific cells using antibody-peptide fusions

Because of their favorable properties as macromolecular drugs, antibodies are a very successful therapeutic modality for interfering with disease-relevant targets in the extracellular space or at the cell membrane. However, a large number of diseases involve cytosolic targets and designing antibodies able to efficiently reach intracellular compartments would expand the antibody-tractable conditions. Here, we genetically fused cell penetrating peptides (CPPs) at various positions to an antibody targeting cancer cells, evaluated the developability features of the resulting antibody-peptide fusions and the ability of selected constructs to reach the cytosol. We first determined positions in the IgG structure that were permissive to CPP incorporation without destabilizing the antibody. Fusing CPPs to the C-terminus of the light chain and either before or after the hinge had the least effect on antibody developability features. These constructs were further evaluated for cell penetration efficiency. Two out of five tested CPPs significantly enhanced antibody penetration into the cytosol, in particular when fused before or after the hinge. Finally, we demonstrate that specific antibody binding to the cell surface target is necessary for efficient cell penetration of the CPP-antibody fusions. This study provides a solid basis for further exploration of therapeutic antibodies for intracellular targets.

Combined NK Cell Therapy and Radiation Therapy Exhibit Long-Term Therapeutic and Antimetastatic Effects in a Human Triple Negative Breast Cancer Model

We investigated whether adoptive cell therapy with ex vivo-activated natural killer (NK) cells enhances the therapeutic efficacy of local tumor radiation therapy (RT) using a human triple-negative breast cancer xenograft model. NK cells from healthy donors were expanded exvivo. MDA-MB-231/Luc-GFP cells were subcutaneously implanted into the thighs of NSG mice. The animals were divided into 4 experimental groups: control, RT, NK, and RT + NK. On day 17 after tumor implantation, tumors from the RT groups were irradiated. The ex vivo-expanded NK cells were intravenously administered twice, on days 17 and 19. Primary and secondary tumors were evaluated using long-term bioluminescence imaging, and histopathology was performed on resected tumor tissue specimens. The luciferase signals of the primary tumors in the RT + NK group were significantly lower than those of comparably sized primary tumors in the RT group. The long-term migration and infiltration of NK cells into the primary tumor sites were significantly higher in RT + NK than in NK mice. Moreover, lymphatic metastasis to the axillary lymph nodes and liver and lung metastases were highly suppressed in the RT + NK group, as demonstrated by BLI and p53 immunohistochemistry. The long-term survival of the RT + NK group was significantly higher than that of the RT or NK groups. Reduction in tumor burden by combining RT and systemic NK cell therapy improved the suppression of primary tumor growth, with efficient NK cell migration and penetration into the primary tumor site. Administered NK cells were maintained in the primary tissue for a significantly longer time in RT + NK group compared with NK group. Both lymphatic spread and distant metastasis to the lungs and liver were effectively suppressed by the combined therapy.

Polymeric Drug Delivery System with Actively Targeted Cell Penetration and Nuclear Targeting for Cancer Therapy.

Targeted tumor cell killing using polymeric micelles with active targeting strategies has been demonstrated to be effectively therapeutic for liver cancers. To implement this strategy, enhancing the cellular uptake of the drug delivery system with targeted anticancer drugs, such as doxorubicin toward nuclear targeting, is of vital importance for increasing drug efficiency and reducing the systemic side effects of encapsulated drugs. In this study, a multifunctional polymeric drug delivery system was designed with actively targeted cell penetration and nuclear targeting for efficient cancer therapy. The nanocarriers were self-assembled from poly(ethylene glycol)-block-poly(ε-caprolactone), decorated with folic acid (FA-PECL) for active targeting via amide reaction for selective delivery of drugs to tumors. A cell penetration peptide (CPP) was decorated with doxorubicin (DOX), and the conjugate (CPP-DOX) was encapsulated in the carrier system for efficient cell penetration and nuclear targeting of drugs. An in vitro study showed an enhanced in vitro cytotoxicity and showed that the tumor volume decreased more than 5 times compared with the nontargeted system, by utilizing the drug-loaded system (FA-PECL/CPP-DOX) with active tumor cell targeting and subsequent nuclear targeting. The FA-PECL/CPP-DOX drug-loading system was well-targeted and enriched on tumor sites, resulting in significant suppression of the liver tumor growth.

Efficient cell penetration and delivery of peptide nucleic acids by an argininocalix[4]arene

The application of Peptide Nucleic Acids (PNAs), mimics of DNA lacking the sugar-phosphate backbone, for antisense/anti-gene therapy and gene editing is limited by their low uptake by cells. Currently, no simple and efficient delivery systems and methods are available to solve this open issue. One of the most promising approach is the modification of the PNA structure through the covalent linkage of poliarginine tails, but this means that every PNA intended to be internalized must be modified. Herein we report the results relative to the delivery ability of a macrocyclic multivalent tetraargininocalix[4]arene (1) used as non-covalent vector for anti-miR-221-3p PNAs. High delivery efficiency, low cytotoxicity, maintenance of the PNA biological activity and ease preparation of the transfection formulation, simply attained by mixing PNA and calixarene, candidate this vector as universal delivery system for this class of nucleic acid analogues.

Nanoscale vesicles assembled from non-planar cyclic molecules for efficient cell penetration.

A new approach to the development of functional biomaterials is to obtain a controllable nanostructure through supramolecular self-assembly. Although much effort has been devoted to supramolecular structures with different morphologies and properties, fluorescent macrocycle-based carbon material assembly into three-dimensional vesicle morphologies remains a challenge. Herein, the supramolecular properties of cycloparaphenylene (CPP) in a mixed solution are characterized and controlled successfully through the regulation of different concentrations and solvent ratios. The self-assembled CPP molecules form a three-dimensional hollow structure in different solutions. The assembled vesicle structure endows CPPs with cell biology application and it is found that CPPs could be internalized by cells via an energy- or temperature-independent mechanism. Even in the presence of different inhibitors, cellular uptake of [10]CPP could not be affected. These supramolecular and biological findings of CPPs extend the current understanding of cycloparaphenylene chemistry and will open up new and more attractive applications in nanotechnology, biology and materials science.

A novel amphipathic cell-penetrating peptide based on the N-terminal glycosaminoglycan binding region of human apolipoprotein E

In the direct cell membrane penetration, arginine-rich cell-penetrating peptides are thought to penetrate into cells across the hydrophobic lipid membranes. To investigate the effect of the amphipathic property of arginine-rich peptide on the cell-penetrating ability, we designed a novel amphipathic cell-penetrating peptide, A2-17, and its derivative, A2-17KR, in which all lysine residues are substituted with arginine residues, based on the glycosaminoglycan binding region in the N-terminal α-helix bundle of human apolipoprotein E. Isothermal titration calorimetry showed that A2-17 variants have a strong ability to bind to heparin with high affinity. Circular dichroism and tryptophan fluorescence measurements demonstrated that A2-17 variants bind to lipid vesicles with a structural change from random coil to amphipathic α-helix, being inserted into the hydrophobic membrane interiors. Flow cytometric analysis and confocal laser scanning microscopy demonstrated the great cell penetration efficiency of A2-17 variants into CHO-K1 cells when incubated at low peptide concentrations (2 μM or less), suggesting that the increased amphipathicity with α-helix formation enhances the cell membrane penetration ability of arginine-rich peptides. Interestingly, A2-17KR exhibited lower efficiency of cell membrane penetration compared to A2-17 despite of their similar binding affinity to lipid membranes. Since high peptide concentrations (typically >10 μM) are usually prerequisite for efficient cell penetration of arginine-rich peptides, A2-17 is a unique amphipathic cell-penetrating peptide that exhibits an efficient cell penetration ability even at low peptide concentrations.

Synthesis of Water-soluble, Polyester-based Dendrimer Prodrugs for Exploiting Therapeutic Properties of Two Triterpenoid Acids

Dendrimers are macromolecules characterized by high controlled size, shape and architecture, presence of inner cavities able to accommodate small molecules and many peripheral functional groups to bind target entities. They are of eminent interest for biomedical applications, including gene transfection, tissue engineering, imaging, and drug delivery. The well-known pharmacological activities of ursolic and oleanolic acids are limited by their small water solubility, non-specific cell distribution, low bioavailability, poor pharmacokinetics, and their direct administration could result in the release of thrombi. To overcome such problems, in this paper we described their physical incorporation inside amino acids-modified polyester-based dendrimers which made them highly water-soluble. IR, NMR, zeta potential, mean size of particles, buffer capacity and drug release profiles of prepared materials were reported. The achieved water-soluble complexes harmonize a polycationic character and a buffer capacity which presuppose efficient cell penetration and increased residence time with a biodegradable cell respectful scaffold, thus appearing as a promising team of not toxic prodrugs for safe administration of ursolic and oleanolic acids.

Mitochondria-Targeting Peptoids.

Mitochondria-specific delivery methods offer a valuable tool for studying mitochondria-related diseases and provide breakthroughs in therapeutic development. Although several small-molecule and peptide-based transporters have been developed, peptoids, proteolysis-resistant peptidomimetics, are a promising alternative to current approaches. We designed a series of amphipathic peptoids and evaluated their cellular uptake and mitochondrial localization. Two peptoids with cyclohexyl residues demonstrated highly efficient cell penetration and mitochondrial localization without significant adverse effects on the cells and mitochondria. These mitochondria-targeting peptoids could facilitate the selective and robust targeted delivery of bioactive compounds, such as drugs, antioxidants, and photosensitizers, with minimal off-target effects.

Effective in vivo gene delivery with reduced toxicity, achieved by charge and fatty acid -modified cell penetrating peptide

Non-viral gene delivery systems have gained considerable attention as a promising alternative to viral delivery to treat diseases associated with aberrant gene expression. However, regardless of extensive research, only a little is known about the parameters that underline in vivo use of the nanoparticle-based delivery vectors. The modest efficacy and low safety of non-viral delivery are the two central issues that need to be addressed. We have previously characterized an efficient cell penetrating peptide, PF14, for in vivo applications. In the current work, we first develop an optimized formulation of PF14/pDNA nanocomplexes, which allows removal of the side-effects without compromising the bioefficacy in vivo. Secondly, based on the physicochemical complex formation studies and biological efficacy assessments, we develop a series of PF14 modifications with altered charge and fatty acid content. We show that with an optimal combination of overall charge and hydrophobicity in the peptide backbone, in vivo gene delivery can be augmented. Further combined with the safe formulation, systemic gene delivery lacking any side effects can be achieved.

Microporous Polyurethane Thin Layer as a Promising Scaffold for Tissue Engineering.

The literature describes that the most efficient cell penetration takes place at 200–500 µm depth of the scaffold. Many different scaffold fabrication techniques were described to reach these guidelines. One such technique is solvent casting particulate leaching (SC/PL). The main advantage of this technique is its simplicity and cost efficiency, while its main disadvantage is the scaffold thickness, which is usually not less than 3000 µm. Thus, the scaffold thickness is usually far from the requirements for functional tissue reconstruction. In this paper, we report a successful fabrication of the microporous polyurethane thin layer (MPTL) of 1 mm thick, which was produced using SC/PL technique combined with phase separation (PS). The obtained MPTL was highly porous (82%), had pore size in the range of 65–426 µm and scaffold average pore size was equal to 154 ± 3 µm. Thus, it can be considered a suitable scaffold for tissue engineering purpose, according to the morphology criterion. Polyurethane (PUR) processing into MPTL scaffold caused significant decrease of contact angle from 78 ± 4° to 56 ± 6° and obtained MPTL had suitable hydrophilic characteristic for mammalian cells growth and tissue regeneration. Mechanical properties of MPTL were comparable to the properties of native tissues. As evidenced by biotechnological examination the MPTL were highly biocompatible with no observed apparent toxicity on mouse embryonic NIH 3T3 fibroblast cells. Performed studies indicated that obtained MPTL may be suitable scaffold candidate for soft TE purposes such as blood vessels.

A highly efficient cell penetrating peptide pVEC-mediated protein delivery system into microalgae

Interest in microalgae has significantly increased due to its potential as a promising bioresource in various fields. However, a technique for intracellular delivery of proteins into microalgae has not established yet, although it is potentially valuable for advanced algal research. Here, we propose a cell penetrating peptide pVEC-mediated protein delivery tool for microalgae. We discovered that the peptide pVEC from vascular endothelial cadherin was more effective in transporting exogenous proteins into algal cells than other peptides including R9, Transportan, TAT and Penetratin. pVEC-mediated tool was shown to deliver proteins of various sizes from 6kDa to 150kDa into wild-type Chlamydomonas reinhardtii and to also work in other algal species such as Nannochloropsis salina and Chlorella vulgaris when delivering a 66kDa protein. In addition, we show that our proposed pVEC-mediated protein delivery system is based on both the endocytic and non-endocytic pathways simultaneously through a mechanism study using inhibitors such as low temperature, N-ethylmaleimide, 5-(N-ethyl-N-isopropyl) amiloride, chlorpromazine, sodium azide, and methyl-beta-cyclodextrin. The results show that the proposed simple and efficient protein delivery tool could contribute to advanced algal research for a wide array of applications for microalgae in various industries.

A peptide functionalized nanomotor as an efficient cell penetrating tool.

A nanomotor based strategy for fast cellular entry and cargo delivery is presented. The concept focuses on integrating tat peptide, a basic domain of HIV-1 tat protein, with state of the art nanomotors which possess attractive autonomous properties, facilitating cellular penetration and uptake. The rapid cellular internalization process leads to higher delivery efficiency.