Structure-activity relationships of water-soluble cationic methacrylate/methacrylamide polymers for nonviral gene delivery

Recent Progress in the Endosomal Escape Mechanism and Chemical Structures of Polycations for Nucleic Acid Delivery

Nucleic acid-based therapies are seeing a spiralling surge. Stimuli-responsive polymers, especially pH-responsive ones, are gaining widespread attention because of their ability to efficiently deliver nucleic acids. These polymers can be synthesized and modified according to target requirements, such as delivery sites and the nature of nucleic acids. In this regard, the endosomal escape mechanism of polymer-nucleic acid complexes (polyplexes) remains a topic of considerable interest owing to various plausible escape mechanisms. This review describes current progress in the endosomal escape mechanism of polyplexes and state-of-the-art chemical designs for pH-responsive polymers. The importance is also discussed of the acid dissociation constant (i.e., pKa) in designing the new generation of pH-responsive polymers, along with assays to monitor and quantify the endosomal escape behavior. Further, the use of machine learning is addressed in pKa prediction and polymer design to find novel chemical structures for pH responsiveness. This review will facilitate the design of new pH-responsive polymers for advanced and efficient nucleic acid delivery.

Strategies for the Nuclear Delivery of Metal Complexes to Cancer Cells

The nucleus is an essential organelle for the function of cells. It holds most of the genetic material and plays a crucial role in the regulation of cell growth and proliferation. Since many antitumoral therapies target nucleic acids to induce cell death, tumor-specific nuclear drug delivery could potentiate therapeutic effects and prevent potential off-target side effects on healthy tissue. Due to their great structural variety, good biocompatibility, and unique physico-chemical properties, organometallic complexes and other metal-based compounds have sparked great interest as promising anticancer agents. In this review, strategies for specific nuclear delivery of metal complexes are summarized and discussed to highlight crucial parameters to consider for the design of new metal complexes as anticancer drug candidates. Moreover, the existing opportunities and challenges of tumor-specific, nucleus-targeting metal complexes are emphasized to outline some new perspectives and help in the design of new cancer treatments.

Nanogels: Smart tools to enlarge the therapeutic window of gene therapy

Gene therapy can potentially treat a great number of diseases, from cancer to rare genetic disorders. Very recently, the development and emergency approval of nucleic acid-based COVID-19 vaccines confirmed its strength and versatility. However, gene therapy encounters limitations due to the lack of suitable carriers to vectorize therapeutic genetic material inside target cells. Nanogels are highly hydrated nano-size crosslinked polymeric networks that have been used in many biomedical applications, from drug delivery to tissue engineering and diagnostics. Due to their easy production, tunability, and swelling properties they have called the attention as promising vectors for gene delivery. In this review, nanogels are discussed as vectors for nucleic acid delivery aiming to enlarge gene therapy's therapeutic window. Recent works highlighting the optimization of inherent transfection efficiency and biocompatibility are reviewed here. The importance of the monomer choice, along with the internal structure, surface decoration, and responsive features are outlined for the different transfection modalities. The possible sources of toxicological endpoints in nanogels are analyzed, and the strategies to limit them are compared. Finally, perspectives are discussed to identify the remining challenges for the nanogels before their translation to the market as transfection agents.

Cellular uptake and fate of cationic polymer-coated nanodiamonds delivering siRNA: a mechanistic study

Gene silencing using small interfering RNAs (siRNAs) is a selective and promising approach for treatment of numerous diseases. However, broad applications of siRNAs are compromised by their low stability in a biological environment and limited ability to penetrate cells. Nanodiamonds (NDs) coated with cationic polymers can enable cellular delivery of siRNAs. Recently, we developed a new type of ND coating based on a random copolymer consisting of (2-dimethylaminoethyl) methacrylate (DMAEMA) and N-(2-hydroxypropyl) methacrylamide (HPMA) monomers. These hybrid ND-polymer particles (Cop+-FND) provide near-infrared fluorescence, form stable complexes with siRNA in serum, show low toxicity, and effectively deliver siRNA into cells in vitro and in vivo. Here, we present data on the mechanism of cellular uptake and cell trafficking of Cop+-FND : siRNA complexes and their ability to selectively suppress mRNA levels, as well as their cytotoxicity, viability and colloidal stability. We identified clathrin-mediated endocytosis as the predominant entry mechanism for Cop+-FND : siRNA into U-2 OS human bone osteosarcoma cells, with a substantial fraction of Cop+-FND : siRNA following the lysosome pathway. Cop+-FND : siRNA potently inhibited the target GAPDH gene with negligible toxicity and sufficient colloidal stability. Based on our results, we suggest that Cop+-FND : siRNA can serve as a suitable in vivo delivery system for siRNA.

Highly Sustainable Dyes Adsorption in Wastewater Using Textile Filters Fabricated by UV Irradiation

Vast amounts of dyeing wastewater released from the textile industry can not only cause water pollution but also have negative effects on the human body, such as skin irritation and respiratory diseases. Dye adsorption technology is necessary for the treatment of wastewater discharged from the dyeing industry and for environmental improvement. However, to remove dyeing wastewater, more energy and solvents are used to fabricate adsorbents, or excessive energy is used to filter dyeing wastewater out, resulting in more environmental pollution. Therefore, it is necessary to develop a method of filtering dyeing wastewater in a more environmentally friendly manner by minimizing the use of solvents and energy. In this study, we modified the surface of a textile substrate through UV irradiation to create a monomer capable of facilely bonding with dyes. Employing the UV photografting method, we were able to produce a dye adsorption filter in a more environmentally friendly manner, minimizing solvent usage and heat energy consumption required for absorbent synthesis. At a monomer concentration of 10%, the fabricated filter exhibited a dye removal efficiency of 97.34% after 24 h, all without the need for a pressure treatment or temperature increase. Moreover, it displayed an adsorption capacity of approximately 77.88 mg per 1 g of filter material.

CO2-Switchable colloids

The development and design of CO2-switchable colloidal particles is described. A presentation of the principles of CO2 switching, especially as they apply to colloids, is followed by recent progress in the preparation of several types of colloidal particles (polymer nanoparticles, metal-organic frameworks (MOFs), quantum dots, graphene, cellulose nanocrystals, carbon nanotubes) for various applications (Pickering stabilizers, catalysts, latexes), and our perspective on future opportunities.

Scalable Air-Tolerant μL-Volume Synthesis of Thick Poly(SPMA) Brushes Using SI-ARGET-ATRP

We present a facile procedure for preparing thick (up to 300 nm) poly(3-sulfopropyl methacrylate) brushes using SI-ARGET-ATRP by conducting the reaction in a fluid film between the substrate and a coverslip. This method is advantageous in a number of ways: it does not require deoxygenation of the reaction solution, and the monomer conversion is much higher than usual since only a minimal amount of solution (microliters) is used, resulting in a tremendous reduction (∼50×) of wasted reagents. Moreover, this method is particularly suitable for grafting brushes to large substrates.

pH-Responsive Biomaterials for the Treatment of Dental Caries-A Focussed and Critical Review

Dental caries is a common and costly multifactorial biofilm disease caused by cariogenic bacteria that ferment carbohydrates to lactic acid, demineralizing the inorganic component of teeth. Therefore, low pH (pH 4.5) is a characteristic signal of the localised carious environment, compared to a healthy oral pH range (6.8 to 7.4). The development of pH-responsive delivery systems that release antibacterial agents in response to low pH has gained attention as a targeted therapy for dental caries. Release is triggered by high levels of acidogenic species and their reduction may select for the establishment of health-associated biofilm communities. Moreover, drug efficacy can be amplified by the modification of the delivery system to target adhesion to the plaque biofilm to extend the retention time of antimicrobial agents in the oral cavity. In this review, recent developments of different pH-responsive nanocarriers and their biofilm targeting mechanisms are discussed. This review critically discusses the current state of the art and innovations in the development and use of smart delivery materials for dental caries treatment. The authors' views for the future of the field are also presented.

The nanostructure of polyelectrolyte complexes of QPDMAEMA-b-POEGMA copolymers and oppositely charged polyelectrolytes, and their stability in the presence of serum albumin

Quaternized poly(2-(dimethylamino) ethyl methacrylate)-b-poly(oligo(ethyleneglycol) methyl ether methacrylate) (QPDMAEMA-b-POEGMA) is a copolymer of a positively charged block and a non-ionic hydrophilic block. The positively charged block, QPDMAEMA, electrostatically interacts with oppositely charged polymers, e.g., poly(acrylic acid) (PAA) and DNA, to form a complex. This complex is stable in aqueous solution due to the hydrophilic block, POEGMA, which provides colloidal stability and biocompatibility. Polyplexes can be used as non-viral vectors in gene therapy. Polyplexes are essential for delivering genetic materials into cells because they protect the genetic material from degradation before reaching the target cells, thus increasing the transfection efficiency. However, currently used polyplexes show a low transfection efficiency in vivo, probably because the polyplexes are exposed to blood proteins, such as serum albumin, which cause their dissociation. The main goal of this research is the morphology characterization of QPDMAEMA-b-POEGMA complexes with the sodium salt of polyacrylic acid (NaPAA), and with DNA by cryogenic transmission electron microscopy (cryo-TEM) and small-angle X-ray scattering (SAXS). These methods give qualitative and quantitative data about the morphology of the complexes. The morphology of the complexes was examined at different charge ratios (CRs). Complexes with NaPAA form core-corona spherical micelles and vesicular structures, whereas complexes with DNA form lamellar and hexagonal structures. The QPDMAEMA-b-POEGMA and DNA complexes were also examined after exposing them to bovine serum albumin (BSA). We found that BSA does not affect the complexes for seven days. This morphology characterization is essential for better design and formulation of vectors for gene therapy and polyelectrolyte complexes for biomedical applications.

Targeted downregulation of MYC mediated by a highly efficient lactobionic acid-based glycoplex to enhance chemosensitivity in human hepatocellular carcinoma cells

The chemosensitization of tumor cells by gene therapy represents a promising strategy for hepatocellular carcinoma (HCC) treatment. In this regard, HCC-specific and highly efficient gene delivery nanocarriers are urgently needed. For this purpose, novel lactobionic acid-based gene delivery nanosystems were developed to downregulate c-MYC expression and sensitize tumor cells to low concentration of sorafenib (SF). A library of tailor-made cationic glycopolymers, based on poly(2-aminoethyl methacrylate hydrochloride) (PAMA) and poly(2-lactobionamidoethyl methacrylate) (PLAMA) were synthesized by a straightforward activators regenerated by electron transfer atom transfer radical polymerization. The nanocarriers prepared with PAMA₁₁₄-co-PLAMA₂₀ glycopolymer were the most efficient for gene delivery. These glycoplexes specifically bound to the asialoglycoprotein receptor and were internalized through the clathrin-coated pit endocytic pathway. c-MYC expression was significantly downregulated by MYC short-hairpin RNA (MYC shRNA), resulting in efficient inhibition of tumor cells proliferation and a high levels apoptosis in 2D and 3D HCC-tumor models. Moreover, c-MYC silencing increased the sensitivity of HCC cells to SF (IC₅₀ for MYC shRNA+ SF 1.9 μM compared to 6.9 μM for control shRNA + SF). Overall, the data obtained demonstrated the great potential of PAMA₁₁₄-co-PLAMA₂₀/MYC shRNA nanosystems combined with low doses of SF for the treatment of HCC.

Influence of DNA Type on the Physicochemical and Biological Properties of Polyplexes Based on Star Polymers Bearing Different Amino Functionalities

The interactions of two star polymers based on poly (2-(dimethylamino)ethyl methacrylate) with different types of nucleic acids are investigated. The star polymers differ only in their functionality to bear protonable amino or permanently charged quaternary ammonium groups, while DNAs of different molar masses, lengths and topologies are used. The main physicochemical parameters of the resulting polyplexes are determined. The influence of the polymer' functionality and length and topology of the DNA on the structure and properties of the polyelectrolyte complexes is established. The quaternized polymer is characterized by a high binding affinity to DNA and formed strongly positively charged, compact and tight polyplexes. The parent, non-quaternized polymer exhibits an enhanced buffering capacity and weakened polymer/DNA interactions, particularly upon the addition of NaCl, resulting in the formation of less compact and tight polyplexes. The cytotoxic evaluation of the systems indicates that they are sparing with respect to the cell lines studied including osteosarcoma, osteoblast and human adipose-derived mesenchymal stem cells and exhibit good biocompatibility. Transfection experiments reveal that the non-quaternized polymer is effective at transferring DNA into cells, which is attributed to its high buffering capacity, facilitating the endo-lysosomal escape of the polyplex, the loose structure of the latter one and weakened polymer/DNA interactions, benefitting the DNA release.

Well-Defined pH-Responsive Self-Assembled Block Copolymers for the Effective Codelivery of Doxorubicin and Antisense Oligonucleotide to Breast Cancer Cells

The worldwide steady increase in the number of cancer patients motivates the development of innovative drug delivery systems for combination therapy as an effective clinical modality for cancer treatment. Here, we explored a design concept based on poly(ethylene glycol)-b-poly(2-(dimethylamino)ethyl methacrylate)-b-poly(2-hydroxyethyl methacrylate-formylbenzoic acid) [PEG-b-PDMAEMA-b-P(HEMA-FBA)] for the dual delivery of doxorubicin (DOX) and GTI2040 (an antisense oligonucleotide for ribonucleotide reductase inhibition) to MCF-7 breast cancer cells. PEG-b-PDMAEMA-b-PHEMA, the precursor copolymer, was prepared through chain extensions from a PEG-based macroinitiator via two consecutive atom transfer radical polymerization (ATRP) steps. Then, it was modified at the PHEMA block with 4-formylbenzoic acid (FBA) to install reactive aldehyde moieties. A pH-responsive polymer-drug conjugate (PDC) was obtained by conjugating DOX to the polymer structure via acid-labile imine linkages, and subsequently self-assembled in an aqueous solution to form DOX-loaded self-assembled nanoparticles (DOX-SAN) with a positively charged shell. DOX-SAN condensed readily with negatively charged GTI2040 to form GTI2040/DOX-SAN nanocomplexes. Gel-retardation assay confirmed the affinity between GTI2040 and DOX-SAN. The GTI2040/DOX-SAN nanocomplex at N/P ratio of 30 exhibited a volume-average hydrodynamic size of 136.4 nm and a zeta potential of 21.0 mV. The pH-sensitivity of DOX-SAN was confirmed by the DOX release study based on the significant cumulative DOX release at pH 5.5 relative to pH 7.4. Cellular uptake study demonstrated favorable accumulation of GTI2040/DOX-SAN inside MCF-7 cells compared with free GTI2040/DOX. In vitro cytotoxicity study indicated higher therapeutic efficacy of GTI2040/DOX-SAN relative to DOX-SAN alone because of the downregulation of the R2 protein of ribonucleotide reductase. These outcomes suggest that the self-assembled pH-responsive triblock copolymer is a promising platform for combination therapy, which may be more effective in combating cancer than individual therapies.

Application of vinyl polymer-based materials as nucleic acids carriers in cancer therapy

Nucleic acid-based therapies have changed the paradigm of cancer treatment, where conventional treatment modalities still have several limitations in terms of efficacy and severe side effects. However, these biomolecules have a short half-life in vivo, requiring multiple administrations, resulting in severe suffering, discomfort, and poor patient compliance. In the early days of (nano)biotechnology, these problems caused concern in the medical community, but recently it has been recognized that these challenges can be overcome by developing innovative formulations. This review focuses on the use of vinyl polymer-based materials for the protection and delivery of nucleic acids in cancer. First, an overview of the properties of nucleic acids and their versatility as drugs is provided. Then, key information on the achievements to date, the most effective delivery methods, and the evaluation of functionalization approaches (stimulatory strategies) are critically discussed to highlight the importance of vinyl polymers in the new cancer treatment approaches. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures.

Polycation Architecture Affects Complexation and Delivery of Short Antisense Oligonucleotides: Micelleplexes Outperform Polyplexes

Herein, we examine the complexation and biological delivery of a short single-stranded antisense oligonucleotide (ASO) payload with four polymer derivatives that form two architectural variants (polyplexes and micelleplexes): a homopolymer poly(2-dimethylaminoethyl methacrylate) (D), a diblock polymer poly(ethylene glycol)methylether methacrylate-block-poly(2-dimethylaminoethyl methacrylate) (O_bD), and two micelle-forming variants, poly(2-dimethylaminoethyl methacrylate)-block-poly(n-butyl methacrylate) (DB) and poly(ethylene glycol)methylether methacrylate-block-poly(2-dimethylaminoethyl methacrylate)-block-poly(n-butyl methacrylate) (O_bDB). Both polyplexes and micelleplexes complexed ASOs, and the incorporation of an O_b brush enhances colloidal stability. Micellplexes are templated by the size and shape of the unloaded micelle and that micelle-ASO complexation is not sensitive to formulation/mixing order, allowing ease, versatility, and reproducibility in packaging short oligonucleotides. The DB micelleplexes promoted the largest gene silencing, internalization, and tolerable toxicity while the O_bDB micelleplexes displayed enhanced colloidal stability and highly efficient payload trafficking despite having lower cellular uptake. Overall, this work demonstrates that cationic micelles are superior delivery vehicles for ASOs denoting the importance of vehicle architecture in biological performance.

Electrical Response of Poly(N-[3-(dimethylamino)Propyl] Methacrylamide) to CO2 at a Long Exposure Period

Amine-functionalized polymers (AFPs) are able to react with carbon dioxide (CO₂) and are therefore useful in CO₂ capture and sensing. To develop AFP-based CO₂ sensors, it is critical to examine their electrical responses to CO₂ over long periods of time, so that the device can be used consistently for measuring CO₂ concentration. To this end, we synthesized poly(N-[3-(dimethylamino)propyl] methacrylamide) (pDMAPMAm) by free radical polymerization and tested its ability to behave as a CO₂-responsive polymer in a transducer. The electrical response of this polymer to CO₂ upon long exposure times was measured in both the aqueous and solid phases. Direct current resistance measurement tests on pDMAPMAm films printed along with the silver electrodes in the presence of CO₂ at various concentrations reveal a two-region electrical response. Upon continuous exposure to different CO₂ flow rates (at a constant pressure of 0.2 MPa), the resistance first decreased over time, reaching a minimum, followed by a gradual increase with further exposure to CO₂. A similar trend is observed when CO₂ is introduced to an aqueous solution of pDMAPMAm. The in situ monitoring of pH suggests that the change in resistance of pDMAPMAm can be attributed to the protonation of tertiary amine groups in the presence of CO₂. This two-region response of pDMAPMAm is based on a proton-hopping mechanism and a change in the number of free amines when pDMAPMAm is exposed to various levels of CO₂.

Improved mechanical properties of antimicrobial poly(N-[3-(dimethylaminopropyl)] methacrylamide) hydrogels prepared by free radical polymerization in the presence of cetyltrimethylammonium bromide as a lyotropic liquid crystal template

The poor mechanical strength of the poly(N-[3-(dimethylamino)propyl] methacrylamide) (PDMAPMAAm) hydrogel limits its application as a drug delivery system and antimicrobial agent. In this study, both its morphology and antibacterial effectiveness were controlled through free radical solution polymerization in the presence of cetyltrimethylammonium bromide (CTAB; cationic nonreactive surfactant), forming lyotropic liquid crystal (LLC) mesophases. All the templated reactions proceeded in four different CTAB concentrations with three different concentrations of DMAPMAAm (2.0, 3.0 and 4.0 mol L^-1), which were carried out in distilled-deionized water (DDW) using potassium persulfate (KPS) and N,N'-methylenebisacrylamide (BIS) as the initiator and crosslinker, respectively. The pH-dependent phase transition temperature (34 °C at pH 14), compression moduli, antibacterial and diffusion properties, and the effect of the LLC mesophases of CTAB on the hydrogel properties were investigated by mechanical measurements, image analysis, inhibition zone tests, X-ray diffractograms and polarized optical microscopy (POM). It was found that the compression moduli of the templated (T)-PDMAPMAAm hydrogels increased by nearly ten times (from ∼3.0 to 30.0 kPa) compared to that of the isotropic (I) ones. The POM and XRD results before the removal of CTAB exhibited the formation of lamellar and hexagonal mesophases. Further, the inhibition zones showed the ability of the I-PDMAPMAAm hydrogels to reduce the activity of E. coli even in the absence of CTAB, gentamicin (GS) and ciprofloxacin (CF). This was because the quaternary ammonium (QA) groups on the DMAPMAAm units could interact with the bacterial membrane.

Formation and stabilization of multiple w/o/w emulsions encapsulating catechin, by mechanical and microfluidic methods using a single pH-sensitive copolymer: effect of copolymer/drug interaction

Multiple w/o/w emulsions (MEs) are promising systems for protecting fragile hydrophilic drugs and controlling their release. We explore the capacity of a single pH-sensitive copolymer, PDMS₆₀-b-PDMAEMA₅₀, and salts, to form and stabilize MEs loaded with sucrose or catechin by a one-step mechanical process or a microfluidic method. ME cytotoxicity was evaluated in various conditions of pH. Using the mechanical process, the most stable emulsions were obtained with Miglyol®812N and isopropyl myristate in a final pH range of 8-12 and [0.3 M-1 M] NaCl concentrations. Conversely, with the microfluidic method, isopropyl myristate at pH 3 without salt was more efficient. Catechin strongly affected the formation of droplets by the mechanical process but did not modify the conditions of stability of MEs obtained by the microfluidic method. The antioxidant power of catechin was preserved in the inner droplets, even in emulsions prepared by the mechanical method at pH 8. An incomplete release of sucrose and catechin from the emulsions was observed and attributed to the interaction of molecules with the copolymer through hydrogen bonding. This study highlights some of the barriers to break to formulate multiple emulsions stabilized by a PDMS-b-PDMAEMA copolymer or other polymers which can form hydrogen bonds interaction with encapsulated drugs.

Effect of pH-sensitive nanoparticles on inhibiting oral biofilms

Dental caries is a biofilm-related preventable infectious disease caused by interactions between the oral bacteria and the host’s dietary sugars. As the microenvironments in cariogenic biofilms are often acidic, pH-sensitive drug delivery systems have become innovative materials for dental caries prevention in recent years. In the present study, poly(DMAEMA-co-HEMA) was used as a pH-sensitive carrier to synthesize a chlorhexidine (CHX)-loaded nanomaterial (p(DH)@CHX). In vitro, p(DH)@CHX exhibited good pH sensitivity and a sustained and high CHX release rate in the acidic environment. It also exhibited lower cytotoxicity against human oral keratinocytes (HOKs) compared to free CHX. Besides, compared with free CHX, p(DH)@CHX showed the same antibacterial effects on S. mutans biofilms. In addition, it had no effect on eradicating healthy saliva-derived biofilm, while free CHX exhibited an inhibitory effect. Furthermore, the 16s rDNA sequencing results showed that p(DH)@CHX had the potential to alter oral microbiota composition and possibly reduce caries risk. In conclusion, the present study presents an alternative option to design an intelligent material to prevent and treat dental caries.

Correia J, Moiseev RV, Cihova M, Gaboriau DCA, Krell J, Khutoryanskiy VV, Stevens MM, Georgiou TK. Investigation of the Thermogelation of a Promising Biocompatible ABC Triblock Terpolymer and Its Comparison with Pluronic F127

Thermoresponsive polymers with the appropriate structure form physical networks upon changes in temperature, and they find utility in formulation science, tissue engineering, and drug delivery. Here, we report a cost-effective biocompatible alternative, namely OEGMA300₁₅-b-BuMA₂₆-b-DEGMA₁₃, which forms gels at low concentrations (as low as 2% w/w); OEGMA300, BuMA, and DEGMA stand for oligo(ethylene glycol) methyl ether methacrylate (MM = 300 g mol^–1), n-butyl methacrylate, and di(ethylene glycol) methyl ether methacrylate, respectively. This polymer is investigated in depth and is compared to its commercially available counterpart, Poloxamer P407 (Pluronic F127). To elucidate the differences in their macroscale gelling behavior, we investigate their nanoscale self-assembly by means of small-angle neutron scattering and simultaneously recording their rheological properties. Two different gelation mechanisms are revealed. The triblock copolymer inherently forms elongated micelles, whose length increases by temperature to form worm-like micelles, thus promoting gelation. In contrast, Pluronic F127’s micellization is temperature-driven, and its gelation is attributed to the close packing of the micelles. The gel structure is analyzed through cryogenic scanning and transmission electron microscopy. Ex vivo gelation study upon intracameral injections demonstrates excellent potential for its application to improve drug residence in the eye.

Amino acid-derived ABCBA-type antifouling biohybrid with multi-stimuli responsivity and contaminant removal capability

A multi-stimuli (pH/thermo/redox)-responsive amphiphilic poly(cysteine methacrylamide)-block-poly(N,N-dimethylaminoethyl methacrylate)-block-polybutadiene-block-poly(N,N-dimethylaminoethyl methacrylate)-block-poly(cysteine methacrylamide) (PCysMAM-b-PDMAEMA-b-PB-b-PDMAEMA-b-PCysMAM) pentablock copolymer biohybrids, based on hydrophobic PB, ampholytic redox responsive PCysMAM and dual (pH and temperature) stimuli responsive PDMAEMA segments,...

Nanoparticle carrier co-delivery of complementary antibiofilm drugs abrogates dual species cariogenic biofilm formation in vitro

Background

Dental caries is a multifactorial disease caused by pathogenic biofilm. In particular, Streptococcus mutans synthesizes biofilm exopolysaccharides, while Candida albicans is associated with the development of severe carious lesions.

Aim

This study aimed to prevent the formation of S. mutans and C. albicans biofilms by exploiting pH-sensitive nanoparticle carriers (NPCs) with high affinity to exopolysaccharides to increase the substantivity of multi-targeted antibiofilm drugs introduced topically in vitro.

Methods

Dual-species biofilms were grown on saliva-coated hydroxyapatite discs with sucrose. Twice-daily, 1.5 min topical treatment regimens of unloaded and drug-loaded NPC were used. Drugs included combinations of two or three compounds with distinct, complementary antibiofilm targets: tt-farnesol (terpenoid; bacterial acid tolerance, fungal quorum sensing), myricetin (flavonoid; exopolysaccharides inhibitor), and 1771 (lipoteichoic acid inhibitor; bacterial adhesion and co-aggregation). Biofilms were evaluated for biomass, microbial population, and architecture.

Results

NPC delivering tt-farnesol and 1771 with or without myricetin completely prevented biofilm formation by impeding biomass accumulation, bacterial and fungal population growth, and exopolysaccharide matrix deposition (vs. control unloaded NPC). Both formulations hindered acid production, maintaining the pH of spent media above the threshold for enamel demineralization. However, treatments had no effect on pre-established dual-species biofilms.

Conclusion

Complementary antibiofilm drug-NPC treatments prevented biofilm formation by targeting critical virulence factors of acidogenicity and exopolysaccharides synthesis.

Study on preparation, compression strength and theophylline/diclofenac sodium release ability of NIPAAm/DMAPMAAm hydrogels

The present study was undertaken to investigate the effect of the composition of the polymerization medium and the type of drug/drug loading process on the mechanical strengths and release profiles of poly(N-isopropylacrylamide-co-N-[3-(dimethylamino)propyl] methacrylamide) P(NIPAAm-co-DMAPMAAm) hydrogels. In line with this goal firstly, the temperature- and pH-responsive hydrogels of NIPAAm and DMAPMAAm were synthesized in three different media at 60 °C: pH 7.4 phosphate-buffered saline (PBS), pH 7.4 phosphate buffer without NaCl/KCl (PB), and distilled-deionized water (pH ≈ 5.5 DDW). The result is that the presence of anionic species such as phosphate (HPO₄^2-/H₂PO₄^-) and chloride (Cl^-) ions in the solution affects on their basic network properties such as volumetric swelling ratio and compression modulus. To evaluate their intermolecular interactions with protonated DMAPMAAm units and drug molecules, depending on composition, type of loading process and drug structure, each of the hydrogels was loaded with diclofenac sodium (DFNa) and theophylline (Thp) by using both diffusion and in situ loading methods. DFNa and Thp release profiles in pH 7.4 PBS at 37 °C were analysed by using zero-order, first-order, Higuchi, Korsmeyer-Peppas, and Peppas-Sahlin models. It has been observed that for the first 60% of DFNa and Thp releases from P(NIPAAm-co-DMAPMAAm) hydrogels synthesized in PB at 60 °C, the contribution of the chain relaxation for the copolymer hydrogels loaded during gelation process was higher than the ones loaded by diffusion process.

Targeting the Inside of Cells with Biologicals: Chemicals as a Delivery Strategy

Delivering macromolecules into the cytosol or nucleus is possible in vitro for DNA, RNA and proteins, but translation for clinical use has been limited. Therapeutic delivery of macromolecules into cells requires overcoming substantially higher barriers compared to the use of small molecule drugs or proteins in the extracellular space. Breakthroughs like DNA delivery for approved gene therapies and RNA delivery for silencing of genes (patisiran, ONPATTRO^®, Alnylam Pharmaceuticals, Cambridge, MA, USA) or for vaccination such as the RNA-based coronavirus disease 2019 (COVID-19) vaccines demonstrated the feasibility of using macromolecules inside cells for therapy. Chemical carriers are part of the reason why these novel RNA-based therapeutics possess sufficient efficacy for their clinical application. A clear advantage of synthetic chemicals as carriers for macromolecule delivery is their favourable properties with respect to production and storage compared to more bioinspired vehicles like viral vectors or more complex drugs like cellular therapies. If biologicals can be applied to intracellular targets, the druggable space is substantially broadened by circumventing the limited utility of small molecules for blocking protein–protein interactions and the limitation of protein-based drugs to the extracellular space. An in depth understanding of the macromolecular cargo types, carrier types and the cell biology of delivery is crucial for optimal application and further development of biologicals inside cells. Basic mechanistic principles of the molecular and cell biological aspects of cytosolic/nuclear delivery of macromolecules, with particular consideration of protein delivery, are reviewed here. The efficiency of macromolecule delivery and applications in research and therapy are highlighted.

Polycation-Mediated Transfection: Mechanisms of Internalization and Intracellular Trafficking

Polyplex-mediated gene transfection is now in its' fourth decade of serious research, but the promise of polyplex-mediated gene therapy has yet to fully materialize. Only approximately one in a million applied plasmids actually expresses. A large part of this is due to an incomplete understanding of the mechanism of polyplex transfection. There is an assumption that internalization must follow a canonical mechanism of receptor mediated endocytosis. Herein, we present arguments that untargeted (and most targeted) polyplexes do not utilize these routes. By incorporating knowledge of syndecan-polyplex interactions, we can show that syndecans are the "target" for polyplexes. Further, it is known that free polycations (which disrupt cell-membranes by acid-catalyzed hydrolysis of phospholipid esters) are necessary for (untargeted) endocytosis. This can be incorporated into the model to produce a novel mechanism of endocytosis, which fits the observed phenomenology. After membrane translocation, polyplex containing vesicles reach the endosome after diffusing through the actin mesh below the cell membrane. From there, they are acidified and trafficked toward the lysosome. Some polyplexes are capable of escaping the endosome and unpacking, while others are not. Herein, it is argued that for some polycations, as acidification proceeds the polyplexes excluding free polycations, which disrupt the endosomal membrane by acid-catalyzed hydrolysis, allowing the polyplex to escape. The polyplex's internal charge ratio is now insufficient for stability and it releases plasmids which diffuse to the nucleus. A small proportion of these plasmids diffuse through the nuclear pore complex (NPC), with aggregation being the major cause of loss. Those plasmids that have diffused through the NPC will also aggregate, and this appears to be the reason such a small proportion of nuclear plasmids express mRNA. Thus, the structural features which promote unpacking in the endosome and allow for endosomal escape can be determined, and better polycations can be designed.

The impact of anionic polymers on gene delivery: how composition and assembly help evading the toxicity-efficiency dilemma

Cationic polymers have been widely studied for non-viral gene delivery due to their ability to bind genetic material and to interact with cellular membranes. However, their charged nature carries the risk of increased cytotoxicity and interaction with serum proteins, limiting their potential in vivo application. Therefore, hydrophilic or anionic shielding polymers are applied to counteract these effects. Herein, a series of micelle-forming and micelle-shielding polymers were synthesized via RAFT polymerization. The copolymer poly[(n-butyl acrylate)-b-(2-(dimethyl amino)ethyl acrylamide)] (P(nBA-b-DMAEAm)) was assembled into cationic micelles and different shielding polymers were applied, i.e., poly(acrylic acid) (PAA), poly(4-acryloyl morpholine) (PNAM) or P(NAM-b-AA) block copolymer. These systems were compared to a triblock terpolymer micelle comprising PAA as the middle block. The assemblies were investigated regarding their morphology, interaction with pDNA, cytotoxicity, transfection efficiency, polyplex uptake and endosomal escape. The naked cationic micelle exhibited superior transfection efficiency, but increased cytotoxicity. The addition of shielding polymers led to reduced toxicity. In particular, the triblock terpolymer micelle convinced with high cell viability and no significant loss in efficiency. The highest shielding effect was achieved by layering micelles with P(NAM-b-AA) supporting the colloidal stability at neutral zeta potential and completely restoring cell viability while maintaining moderate transfection efficiencies. The high potential of this micelle-layer-combination for gene delivery was illustrated for the first time.

Assembly of Defect-Free Microgel Nanomembranes for CO2 Separation

The development of robust and thin CO₂ separation membranes that allow fast and selective permeation of CO₂ will be crucial for rebalancing the global carbon cycle. Hydrogels are attractive membrane materials because of their tunable chemical properties and exceptionally high diffusion coefficients for solutes. However, their fragility prevents the fabrication of thin defect-free membranes suitable for gas separation. Here, we report the assembly of defect-free hydrogel nanomembranes for CO₂ separation. Such membranes can be prepared by coating an aqueous suspension of colloidal hydrogel microparticles (microgels) onto a flat, rough, or micropatterned porous support as long as the pores are hydrophilic and the pore size is smaller than the diameter of the microgels. The deformability of the microgel particles enables the autonomous assembly of defect-free 30-50 nm-thick membrane layers from deformed ∼15 nm-thick discoidal particles. Microscopic analysis established that the penetration of water into the pores driven by capillary force assists the assembly of a defect-free dense hydrogel layer on the pores. Although the dried films did not show significant CO₂ permeance even in the presence of amine groups, the permeance dramatically increased when the membranes are adequately hydrated to form a hydrogel. This result indicated the importance of free water in the membranes to achieve fast diffusion of bicarbonate ions. The hydrogel nanomembranes consisting of amine-containing microgel particles show selective CO₂ permeation (850 GPU, α_CO2/N2 = 25) against post-combustion gases. Acid-containing microgel membranes doped with amines show highly selective CO₂ permeation against post-combustion gases (1010 GPU, α_CO2/N2 = 216) and direct air capture (1270 GPU, α_CO2/N2 = 2380). The membrane formation mechanism reported in this paper will provide insights into the self-assembly of soft matters. Furthermore, the versatile strategy of fabricating hydrogel nanomembranes by the autonomous assembly of deformable microgels will enable the large-scale manufacturing of high-performance separation membranes, allowing low-cost carbon capture from post-combustion gases and atmospheric air.

PAMAM-Functionalized Cellulose Nanocrystals with Needle-Like Morphology for Effective Cancer Treatment

Gene therapy is used to correct or compensate for diseases caused by gene defects and abnormalities. Improving the transfection efficiency and reducing the toxicity of gene carriers are the keys to gene therapy. Similar to a typical cationic gene carrier—polyethylenimine (PEI, 25 kDa)—the polyamidoamine (PAMAM) dendrimer also has a large number of amino groups. These amino groups can be complexed with nucleic acids after protonation under physiological conditions. However, the concentrated positive charge can cause undesirable cytotoxicity. Cellulose nanocrystals (CNCs) have good biocompatibility and unique needle-like morphology, and have been proven to be efficiently taken up by cells. In this article, three-dimensional spherical PMAMA dendrimers are conjugated onto the surface of CNCs to obtain a kind of needle-like cationic carrier (CNC-PAMAM). PAMAM dendrimers act as anchors to bind the plasmid DNAs (pDNA) to the surface of the CNC. The prepared CNC-based carrier showed high transfection efficiency and low toxicity. The CNC-PAMAM can effectively deliver the suicide gene to the tumor site, enabling the suicide gene/prodrug system (cytosine deaminase/5-fluorocytosine (CD/5-FC)) to play an effective anti-tumor role in vivo. This research demonstrates that the functionalization of CNCs with PAMAM dendrimers is an effective method for developing novel gene delivery systems.

Polymeric Delivery of Therapeutic Nucleic Acids

The advent of genome editing has transformed the therapeutic landscape for several debilitating diseases, and the clinical outlook for gene therapeutics has never been more promising. The therapeutic potential of nucleic acids has been limited by a reliance on engineered viral vectors for delivery. Chemically defined polymers can remediate technological, regulatory, and clinical challenges associated with viral modes of gene delivery. Because of their scalability, versatility, and exquisite tunability, polymers are ideal biomaterial platforms for delivering nucleic acid payloads efficiently while minimizing immune response and cellular toxicity. While polymeric gene delivery has progressed significantly in the past four decades, clinical translation of polymeric vehicles faces several formidable challenges. The aim of our Account is to illustrate diverse concepts in designing polymeric vectors towards meeting therapeutic goals of in vivo and ex vivo gene therapy. Here, we highlight several classes of polymers employed in gene delivery and summarize the recent work on understanding the contributions of chemical and architectural design parameters. We touch upon characterization methods used to visualize and understand events transpiring at the interfaces between polymer, nucleic acids, and the physiological environment. We conclude that interdisciplinary approaches and methodologies motivated by fundamental questions are key to designing high-performing polymeric vehicles for gene therapy.

Improved gene delivery to K-562 leukemia cells by lipoic acid modified block copolymer micelles

Although there has been substantial progress in the research field of gene delivery, there are some challenges remaining, e.g. there are still cell types such as primary cells and suspension cells (immune cells) known to be difficult to transfect. Cationic polymers have gained increasing attention due to their ability to bind, condense and mask genetic material, being amenable to scale up and highly variable in their composition. In addition, they can be combined with further monomers exhibiting desired biological and chemical properties, such as antioxidative, pH- and redox-responsive or biocompatible features. By introduction of hydrophobic monomers, in particular as block copolymers, cationic micelles can be formed possessing an improved chance of transfection in otherwise challenging cells. In this study, the antioxidant biomolecule lipoic acid, which can also be used as crosslinker, was incorporated into the hydrophobic block of a diblock copolymer, poly{[2-(dimethylamino)ethyl methacrylate]101-b-[n-(butyl methacrylate)124-co-(lipoic acid methacrylate)22]} (P(DMAEMA101-b-[nBMA124-co-LAMA22])), synthesized by RAFT polymerization and assembled into micelles (LAMA-mic). These micelles were investigated regarding their pDNA binding, cytotoxicity mechanisms and transfection efficiency in K-562 and HEK293T cells, the former representing a difficult to transfect, suspension leukemia cell line. The LAMA-mic exhibited low cytotoxicity at applied concentrations but demonstrated superior transfection efficiency in HEK293T and especially K-562 cells. In-depth studies on the transfection mechanism revealed that transfection efficiency in K-562 cells does not depend on the specific oncogenic fusion gene BCR-ABL alone. It is independent of the cellular uptake of polymer-pDNA complexes but correlates with the endosomal escape of the LAMA-mic. A comparison of the transfection efficiency of the LAMA-mic with structurally comparable micelles without lipoic acid showed that lipoic acid is not solely responsible for the superior transfection efficiency of the LAMA-mic. More likely, a synergistic effect of the antioxidative lipoic acid and the micellar architecture was identified. Therefore, the incorporation of lipoic acid into the core of hydrophobic-cationic micelles represents a promising tailor-made transfer strategy, which can potentially be beneficial for other difficult to transfect cell types.

Solely aqueous formulation of hydrophobic cationic polymers for efficient gene delivery

Cationic polymers are promising gene delivery vectors due to their ability to bind and protect genetic material. The introduction of hydrophobic moieties into cationic polymers can further improve the vector efficiency, but common formulations of hydrophobic polymers involve harsh conditions such as organic solvents, impairing intactness and loading efficiency of the genetic material. In this study, a mild, aqueous formulation method for the encapsulation of high amounts of genetic material is presented. A well-defined pH-responsive hydrophobic copolymer, i.e. poly((n-butylmethacrylate)-co-(methylmethacrylate)-co-(2-(dimethylamino) ethylmethacrylate)), (PBMD) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization. Exploiting the pH-dependent solubility behavior of the polymer, stable pDNA loaded nanoparticles were prepared and characterized using analytical ultracentrifugation (AUC), cryo-transmission electron microscopy (cryo-TEM) and dynamic light scattering (DLS). This novel formulation approach showed high transfection efficiencies in HEK293T cells, while requiring 5- to 10-fold less pDNA compared to linear polyethylenimine (LPEI), in particular at short incubation times and in serum-containing media. Furthermore, the formulation was successfully adopted for siRNA and mRNA encapsulation and the commercially approved polymer Eudragit® E(PO/100). Overall, the aqueous formulation approach, accompanied by a tailor-made hydrophobic polymer and detailed physicochemical and application studies, led to improved gene delivery vectors with high potential for further applications.

Polymer Modification of Lipases, Substrate Interactions, and Potential Inhibition

An industrially important enzyme, Candida antarctica lipase B (CalB), was modified with a range of functional polymers including hydrophilic, hydrophobic, anionic, and cationic character using a "grafting to" approach. We determined the impact of polymer chain length on CalB activity by synthesizing biohybrids of CalB with each polymer at three different chain lengths, using reversible addition-fragmentation chain transfer (RAFT) polymerization. The activity of CalB in both aqueous and aqueous-organic media mixtures was significantly enhanced for acrylamide (Am) and N,N-dimethyl acrylamide (DMAm) conjugates, with activity remaining approximately constant in 25 and 50% ethanol solvent systems. Interestingly, the activity of N,N-dimethylaminopropyl-acrylamide (DMAPA) conjugates increased gradually with increasing organic solvent content in the system. Contrary to other literature reports, our study showed significantly diminished activity for hydrophobic polymer-protein conjugates. Functional thermal stability assays also displayed a considerable enhancement of retained activity of Am, DMAm, and DMAPA conjugates compared to the native CalB enzyme. Thus, this study provides an insight into possible advances in lipase production, which can lead to new improved lipase bioconjugates with increased activity and stability.

The influences of monomer structure and solvent on the radical copolymerization of tertiary amine and PEGylated methacrylates

This work presents a meticulous and rigorous investigation of reactivity ratios of commonly used monomers (PEGMA, DEAEMA, and DMAEMA) with high importance for stimuli-responsive materials; a copolymerization mini-library with 9 systems is reported.

Polymeric nanoparticles for RNA delivery

As exemplified by recent clinical approval of RNA drugs including the latest COVID-19 mRNA vaccines, RNA therapy has demonstrated great promise as an emerging medicine. Central to the success of RNA therapy is the delivery of RNA molecules into the right cells at the right location. While the clinical success of nanotechnology in RNA therapy has been limited to lipid-based nanoparticles currently, polymers, due to their tunability and robustness, have also evolved as a class of promising material for the delivery of various therapeutics including RNAs. This article overviews different types of polymers used in RNA delivery and the methods for the formulation of polymeric nanoparticles and highlights recent progress of polymeric nanoparticle-based RNA therapy.

3D Hybrid Nanofiber Aerogels Combining with Nanoparticles Made of a Biocleavable and Targeting Polycation and MiR-26a for Bone Repair

The healing of large bone defects represents a clinical challenge, often requiring some form of grafting. Three-dimensional (3D) nanofiber aerogels could be a promising bone graft due to their biomimetic morphology and controlled porous structures and composition. miR-26a has been reported to induce the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and facilitate bone formation. Introducing miR-26a with a suitable polymeric vector targeting BMSCs could improve and enhance the functions of 3D nanofiber aerogels for bone regeneration. Herein, we first developed the comb-shaped polycation (HA-SS-PGEA) carrying a targeting component, biocleavable groups and short ethanolamine (EA)-decorated poly(glycidyl methacrylate) (PGMA) (abbreviated as PGEA) arms as miR-26a delivery vector. We then assessed the cytotoxicity and transfection efficiency of this polycation and cellular response to miR-26a-incorporated nanoparticles (NPs) in vitro. HA-SS-PGEA exhibited a stronger ability to transport miR-26a and exert its functions than the gold standard polyethyleneimine (PEI) and low-molecular-weight linear PGEA. We finally examined the efficacy of HA-SS-PGEA/miR-26a NPs loaded 3D hybrid nanofiber aerogels showing a positive effect on the cranial bone defect healing. Together, the combination of 3D nanofiber aerogels and functional NPs consisting of a biodegradable and targeting polycation and therapeutic miRNA could be a promising approach for bone regeneration.

Design, characterization, and intracellular trafficking of biofunctionalized chitosan nanomicelles

The hydrophobically modified glycol chitosan (HGC) nanomicelle has received increasing attention as a promising platform for the delivery of chemotherapeutic drugs. To improve the tumor selectivity of HGC, here an avidin and biotin functionalization strategy was applied. The hydrodynamic diameter of the biotin-avidin-functionalized HGC (cy5.5-HGC-B4F) was observed to be 104.7 nm, and the surface charge was +3.1 mV. Confocal and structured illumination microscopy showed that at 0.1 mg/ml, cy5.5-HGC-B4F nanomicelles were distributed throughout the cytoplasm of MDA-MB-231 breast cancer cells after 2 h of exposure without significant cytotoxicity. To better understand the intracellular fate of the nanomicelles, entrapment studies were performed and demonstrated that some cy5.5-HGC-B4F nanomicelles were capable of escaping endocytic vesicles, likely via the proton sponge effect. Quantitative analysis of the movements of endosomes in living cells revealed that the addition of HGC greatly enhanced the motility of endosomal compartments, and the nanomicelles were transported by early and late endosomes from cell periphery to the perinuclear region. Our results validate the importance of using live-cell imaging to quantitatively assess the dynamics and mechanisms underlying the complex endocytic pathways of nanosized drug carriers.

Predicting the effect of phototherapy method on breast cancer cells by mathematical modeling: UV-IR non-ionization radiation with gold nanoparticles

Phototherapy is a minimally invasive oncological treatment strategy in which photon energy is delivered to the tumor tissue. Gold nanoparticles (GNPs) can enhance photothermal or photodynamic phenomena when excited by a wavelength beam in the range of UV-IR. GNPs are used in phototherapy for cancer cell treatment by controlling the physical and chemical conditions. Given the growing application of GNPs for the treatment of breast cancer, predicting the behavior of cancer cells during exposure to GNPs is of prime importance. However, the prediction might be far from reality due to the inherent complexities associated with the conditions of the treatment methods and the mechanisms involved in cell toxicity. This study provides general information by collecting data on the cytotoxicity of GNPs along with this process. Data mining was performed using a mathematical modeling method called SA-LOOCV-GRBF. In this study, eight parameters including particle size, zeta potential, concentration of GNPs in the cell culture medium, incubation time, light exposure time, maximum wavelength absorbance (MAW) of GNPs, irradiation beam wavelength (IW) and light source power density (PD) were measured. In this modeling, these parameters were considered as model inputs, and the cell viability of breast cancer cells after treatment was treated as the model output. As a result, the physical and chemical properties of GNPs as well as their application conditions wield influence on cytotoxicity. The results help select the desired condition for these nanoparticles in the phototherapy of breast cancer cells.

[12]aneN3-Based Gemini-Type Amphiphiles with Two-Photon Absorption Properties for Enhanced Nonviral Gene Delivery and Bioimaging

Although a plethora of nonviral gene vectors have been developed for potential gene therapy, imageable gemini surfactants with stimuli-responsiveness and high transfection efficiency are still scarce for gene delivery. Herein, three gemini amphiphiles (DEDPP-4/8/12) consisting of an aggregation-induced emission (AIE) central fluorophore: 5,6-diphenylpyrazine-2,3-diester (DEDPP), decorated with triazole-[12]aneN₃ as the hydrophilic moiety and alkyl chains of various lengths as the hydrophobic moiety, were designed and synthesized for trackable gene delivery via optical imaging. All three amphiphiles exhibited ultralow critical micelle concentrations (CMCs) (up to 3.40 × 10^-6 M), prominent two-photon absorption properties, and solvatochromic fluorescence. Gel electrophoresis assays demonstrated that the migration of plasmid DNA was completely retarded after condensation with these gemini amphiphiles at low concentrations (up to 10 μM). In addition, the ester bond in these amphiphiles may facilitate vector degradation and DNA release, in response to esterase and the acidic environment inside cells. Upon self-assembly with DOPE to form liposomes, DEDPP-8/DOPE achieved the best transfection efficiency in four cell lines, and the transfection efficiency of DEDPP-8/DOPE in HeLa cell lines was 23.5-fold higher than that of Lipo2000, which is unusually high for small organic molecule-based nonviral vectors. Furthermore, excellent transfection efficiency of DEDPP-8/DOPE was obtained in the presence of serum, and the red fluorescence protein (RFP) gene was successfully transfected in zebrafish embryos. Both one- and two-photon fluorescence imaging clearly demonstrated the delivery process of plasmid DNA. This study demonstrated that gemini-type amphiphiles composed of a two-photon fluorophore core conjugated with triazole-[12]aneN₃ via an ester bond afforded an unprecedentedly high transfection efficiency with excellent biocompatibility, which may provide new insights for the design and development of multifunctional nonviral gene vectors for imageable gene delivery.