Delineating effect of headgroup and preparation method on transfection versus toxicity of DNA-loaded lipid nanocarriers - supplementary materials

Aim: To perform a parallel comparison of key parameters affecting the safety and efficiency of lipidbased nanovectors (i.e., complexing headgroups, composition and preparation method). Materials & methods: Various cationic and ionizable headgroups were screened for formulating lipoplexes with GFP– plasmid DNA. Ethanol injection and microfluidics were used to prepare nanoparticles with GFP–plasmid DNA complexed on the surface or within the interior of lipid bilayers. Results: Lipoplexes composed of sphingomyelin 102 exhibited the highest transfection efficiency given their higher cellular uptake in BRAF inhibitor-resistant melanoma cells. Lipid nanoparticles demonstrated acceptable transfection efficiency and high spheroid penetration while protecting plasmid DNA under simulated physiological conditions. Conclusion: Selecting the right complexing lipid and preparation method is critical for developing lipid nanocarriers to treat intractable diseases.Plain language summary: Certain genetic diseases or cancers can be treated with gene therapy. This involves the delivery of working genes to cells with a faulty copy. These genes are often contained in a circular piece of DNA called a plasmid. Plasmids can be delivered by a variety of structures called vectors. These vectors include altered viruses as well as lipid-based nanovectors, which are nanoscale spheres of phospholipids, a type of fat. Plasmids can either be internalized inside these spheres in lipid nanoparticles (LNPs) or attached to the surface in nanocomplexes. A section of the phospholipid called the headgroup faces outward in lipid-based nanovectors. The chemical makeup of these headgroups determines the function of the lipid-based nanovector. This study aimed to determine an optimal lipid-based nanovector in gene delivery by testing a variety and identifying which was most effective at delivering a gene that makes cells fluoresce green when successfully delivered. The more intense the fluorescence, the greater the degree of successful gene delivery. This study found that LNPs were more effective at delivering plasmid DNA than nanocomplexes and were safer and protected plasmid DNA better. The best performing LNP contained the lipid sphingomyelin 102, which is biodegradable. Therefore, the optimized LNP formulation employing sphingomyelin 102 as a biodegradable lipid could be an efficient nonviral gene-delivery system and will be further investigated to target drug-resistant melanoma, a type of skin cancer.</p

Electronic spectroscopy of the CaCCCH[subscript 3] and SrCCCH[subscript 3] free radicals

The first spectroscopic observation of the free radicals CaCCCH[subscript 3] and SrCCCH[subscript 3] is reported. Vibrationally-resolved laser-induced fluorescence spectra, which were recorded under supersonic jet conditions, reveal two band systems for each molecule which have been assigned to the à [superscript 2]E–[X with combining tilde] [superscript 2]A[subscript 1] and [B with combining tilde] [superscript 2]A[subscript 1]–[X with combining tilde] [superscript 2]A[subscript 1] electronic transitions. The vibrational structure in each system is limited to a short progression in the metal–carbon stretching mode. The Ö[X with combining tilde] origin is blue-shifted relative to the monoacetylides of Ca and Sr. Furthermore, in contrast to CaCCH and SrCCH, where predissociation seems to reduce the fluorescence quantum yield to near zero, the [B with combining tilde] states of both CaCCCH[subscript 3] and SrCCCH[subscript 3] show strong fluorescence. Although relatively remote from the chromophore (the metal atom), the methyl group perturbs the electronic structure sufficiently to shift the low lying vibrational levels of the [B with combining tilde] state out of the predissociative region

Combination Approach of YSA Peptide Anchored Docetaxel Stealth Liposomes with Oral Antifibrotic Agent for the Treatment of Lung Cancer

Therapeutic efficacy of nanocarriers can be amplified by active targeting and overcoming the extracellular matrix associated barriers of tumors. The aim of the present study was to investigate the effect of oral antifibrotic agent (telmisartan) on tumor uptake and anticancer efficacy of EphA2 receptor targeted liposomes. Docetaxel loaded PEGylated liposomes (DPL) functionalized with nickel chelated phospholipid were prepared using a modified hydration method. DPL were incubated with various concentrations of histidine tagged EphA2 receptor specific peptide (YSA) to optimize particle size, zeta potential, and percentage YSA binding. Cellular uptake studies using various endocytosis blockers revealed that a caveolae dependent pathway was the major route for internalization of YSA anchored liposomes of docetaxel (YDPL) in A549 lung cancer cell line. Hydrodynamic diameter and zeta potential of optimized YDPL were 157.3 ± 11.8 nm and −3.64 mV, respectively. Orthotopic lung tumor xenograft (A549) bearing athymic nude mice treated with oral telmisartan (5 mg/kg) for 2 days showed significantly (<i>p</i> < 0.05) higher uptake of YDPL in tumor tissues compared to healthy tissue. Average lung tumor weight of the YDPL + telmisartan treated group was 4.8- and 3.8-fold lower than that of the DPL and YDPL treated groups (<i>p</i> < 0.05). Substantially lower expression (<i>p</i> < 0.05) of EphA2 receptor protein, proliferating cell nuclear antigen (PCNA), MMP-9, and collagen 1A level with increased E-cadherin and TIMP-1 levels in immunohistochemistry and Western blot analysis of lung tumor samples of the combination group confirmed antifibrotic effect with enhanced anticancer activity. Active targeting and ECM remodeling synergistically contributed to anticancer efficacy of YDPL in orthotopic lung cancer

Expression of HCN1 and HCN4 at HH36.

<p>Whole mount in-situ hybridisation showing expression of <i>HCN1</i> and <i>HCN4</i> in avian lymph heart at HH36 as indicated by red arrow. The expression of these channels was not detected in other stages.</p

Evoked local field potential recorded from lymph heart before and after addition of carbachol followed by atropine in the presence of carbachol.

<p>A) Representative trace of evoked local field potential (LFP) obtained from control, in the presence of carbachol (10μM) B) and after adding atropine (5μM) in the presence of carbachol C). D) Bar charts show average peak to peak of evoked LFP amplitude calculated from control, in the presence of carbachol and after adding atropine in the presence of carbachol (n = 9). The data for evoked LFP in the presence of carbachol and the data for evoked LFP of atropine in the presence of carbachol was normalised to data obtained from control. After adding carbachol the average peak to peak of evoked <b>LFP</b> amplitude was significantly reduced (*** p<0.001) compared to the control. On addition of atropine in the presence of carbachol the effects were significantly reversed (*** p<0.001). Error bars represent mean ± SEM (n = 9). E) Bar chart shows average peak to peak of evoked LFP amplitude calculated from control, in the presence of TTX (n = 3). The data for evoked LFP in the presence of TTX was normalised to data obtained from control. After adding TTX the average peak to peak of evoked LFP was reduced compared to control however it was not statistically significant (p>0.05). Error bars represent mean ± SEM.</p

Summary of the genes regulated during lymph heart development and involvement of ion channels in excitability and rhythmicity of the lymph heart.

<p>The lymph heart predominantly expresses skeletal muscle markers and their expression is evident as early as HH30 and decline<b>s</b> by HH38. By HH36, the lymph heart contracts rhythmically and the basis for their underlying rhythmicity is most likely mediated by HCN channels while their excitation and contraction coupling is facilitated by cholinergic and L-type Ca²⁺ channels.</p

Expression of Prox-1, and Cav1.1 during lymph heart development.

<p>Whole mount in-situ hybridisation showing developmental expression of <i>Prox-1</i> (A1-A4) and <i>Cav1</i>.<i>1</i> (B1-B4) in the lymph heart as indicated by red arrow. The expression of <i>Prox-1</i> and <i>Cav1</i>.<i>1</i> was detected as early as HH30 and declined by HH38.</p

Evoked local field potential recorded from lymph heart before and after addition of cyclopiazonic acid followed by calcium.

<p>A) Representative trace of evoked local field potential (LFP) obtained from control, in the presence of CPA (10μM) B) and after adding Ca²⁺ (2mM) C). D) Bar charts show average peak to peak of evoked LFP amplitude calculated from control, in the presence of CPA and after adding Ca²⁺ (n = 13). The data for the evoked LFP in the presence of CPA and the data for the evoked LFP of Ca²⁺ was normalised to data obtained from control. After adding CPA the average peak to peak of evoked LFP amplitude was significantly reduced (* p<0.05) compared to control. On addition of Ca²⁺ the average peak to peak of evoked LFP amplitude significantly increased compared to CPA (*** p<0.001) and control (* p<0.05). Error bars represent mean ± SEM (n = 13).</p

Expression of cadherins during lymph heart development.

<p>Whole mount in-situ hybridisation showing developmental expression of <i>M-cadherin</i> (A1-A4), <i>N-cadherin</i> (B1-B4), <i>R-cadherin</i> (C1-C4) and <i>T-cadherin</i> (D1-D4) in the lymph heart as indicated by red arrow. The expression of <i>M</i>, <i>N</i>, and <i>R</i>, and <i>T-cadherin</i> was detected as early as HH30 and only <i>M-cadherin</i> was expressed at HH38.</p

Expression of skeletal muscle markers during development of lymph heart.

<p>Whole mount in-situ hybridisation showing developmental expression of <i>Pax-7</i> (A1-A4), <i>MyoD</i> (B1-B4), <i>Myogenin</i> (C1-C4) and Engrailed-1 (<i>En-1</i>) (D1-D4) in the lymph heart as indicated by red arrow. The expression of <i>Pax-7</i>, <i>MyoD</i>, <i>Myogenin and En-1</i> was detected as early as HH30 and declined by HH38.</p