3D-Printed Microcubes for Catalase Drug Delivery

Oxidative stress, i.e., excessive production of reactive oxygen species (ROS), plays an important role in the pathogenesis of inflammatory diseases such as cardiovascular diseases, cancer, and neurodegenerative diseases. Catalase, an antioxidant enzyme, has great therapeutic potential; however, its efficacy is limited by its delivery to target cells or tissues. In order to achieve efficient delivery, consistent drug distribution, and drug activity, small and uniformly sized drug delivery vehicles are needed. Here, three-dimensional (3D) microcubes were printed by Nanoscribe Photonic Professional GT2, a high-resolution 3D printer, and the characteristics of 3D-printed microcubes as drug delivery vehicles for the delivery of catalase were investigated. The size of the 3D-printed microcubes was 800 nm in length of a square and 600 nm in height, which is suitable for targeting macrophages passively. Microcubes were also tunable in shape and size, and high-resolution 3D printing could provide microparticles with little variation in shape and size. Catalase was loaded on 3D-printed microcubes by nonspecific adsorption, and catalase on 3D-printed microcubes (CAT–MC) retained 83.1 ± 1.3% activity of intact catalase. CAT–MC also saved macrophages, RAW 264.7, from the cytotoxicity of H2O2 by 86.4 ± 4.1%. As drug delivery vehicles, 3D-printed microparticles are very promising due to their small and uniform size, which provides consistent drug distribution and drug activity. Therefore, we anticipate numerous applications of 3D-printed microparticles for delivering therapeutic proteins

Inhibition of Human Amylin Aggregation and Cellular Toxicity by Lipoic Acid and Ascorbic Acid

More than 30 human degenerative diseases result from protein aggregation such as Alzheimer’s disease (AD) and type 2 diabetes mellitus (T2DM). Islet amyloid deposits, a hallmark in T2DM, are found in pancreatic islets of more than 90% of T2DM patients. An association between amylin aggregation and reduction in β-cell mass was also established by post-mortem studies. A strategy in preventing protein aggregation-related disorders is to inhibit the protein aggregation and associated toxicity. In this study, we demonstrated that two inhibitors, lipoic acid and ascorbic acid, significantly inhibited amylin aggregation. Compared to amylin (15 μM) as 100%, lipoic acid and ascorbic acid reduced amylin fibril formation to 42.1 ± 17.2% and 42.9 ± 12.8%, respectively, which is confirmed by fluorescence and TEM images. In cell viability tests, both inhibitors protected RIN-m5f β-cells from the toxicity of amylin aggregates. At 10:1 molar ratio of lipoic acid to amylin, lipoic acid with amylin increased the cell viability to 70.3%, whereas only 42.8% RIN-m5f β-cells survived in amylin aggregates. For ascorbic acid, an equimolar ratio achieved the highest cell viability of 63.3% as compared to 42.8% with amylin aggregates only. Docking results showed that lipoic acid and ascorbic acid physically interact with amylin amyloidogenic region (residues Ser20-Ser29) via hydrophobic interactions; hence reducing aggregation levels. Therefore, lipoic acid and ascorbic acid prevented amylin aggregation via hydrophobic interactions, which resulted in the prevention of cell toxicity <i>in vitro</i>

Effects of intracellular treatment with 5- or 40-nm AuNPs on the passive electrical properties of hippocampal CA1 neurons from a mouse hippocampal slice.

<p>(A) DIC images of a brain slice (left, 50×) and hippocampal CA1 layer (middle, 630×), and a fluorescence image of CA1 neurons (right, 630×) loaded with fluorophore-conjugated AuNPs through a patch pipette (middle) after breaking the gigaohm seal. The fluorescence signal indicates the infusion of AuNPs into the cell. (B) Representative traces of membrane potential changes and APs elicited by step-current injections for 1 sec from AuNP-treated and untreated (no AuNPs) hippocampal CA1 neurons. (C) AuNPs of both sizes considerably increased the changes in membrane potential. (D) Input resistance was significantly increased by AuNPs of both sizes. (E) The 5- or 40-nm AuNPs increased the number of APs substantially at low current intensity (at 30- or 60-pA depolarizing current injection). *<i>p</i><0.05, **<i>p</i><0.01, Student's <i>t</i>-test, No AuNPs <i>vs</i>. 40-nm AuNPs; ^#<i>p</i><0.05, Student's <i>t</i>-test, No AuNPs <i>vs</i>. 5-nm AuNPs; ⁺<i>p</i><0.05, Student's <i>t</i>-test, 5-nm AuNPs <i>vs</i>. 40-nm AuNPs.</p

H‑Gemcitabine: A New Gemcitabine Prodrug for Treating Cancer

In this report, we present a new strategy for targeting chemotherapeutics to tumors, based on targeting extracellular DNA. A gemcitabine prodrug was synthesized, termed H-gemcitabine, which is composed of Hoechst conjugated to gemcitabine. H-gemcitabine has low toxicity because it is membrane-impermeable; however, it still has high tumor efficacy because of its ability to target gemcitabine to E-DNA in tumors. We demonstrate here that H-gemcitabine has a wider therapeutic window than free gemcitabine

Effects of intracellular treatment with 5- or 40-nm AuNPs on seizure models.

<p>(A, B) Prolonged SRF experiment. (A) The representative traces of repetitive firings elicited by long (10 sec) depolarizing current pulses. (B) PDS-like spikes, an epiletiform activity, were observed from a portion of AuNP-treated hippocampal CA1 neurons. (C) The representative traces of low Mg²⁺-induced bursts of spikes. Arrow head indicates a burst of spikes. (D) Intracellular 40-nm AuNPs increased the number of bursts. Average number of bursts per min were presented. *<i>p</i><0.05, Student's <i>t</i>-test; N.S., no significance.</p

Effects of intracellular treatment with 5- or 40-nm AuNPs on AP properties in hippocampal CA1 neurons.

<p>(A) AuNPs of both sizes significantly decreased the latency to the first AP. The 40-nm AuNPs significantly reduced the AP threshold (B) and AP duration (C). (D) AuNPs of both sizes significantly increased AHP. (E) AuNPs did not affect the AP amplitude. *<i>p</i><0.05, **<i>p</i><0.01, Student's <i>t</i>-test, No AuNPs <i>vs</i>. 40-nm AuNPs; ^#<i>p</i><0.05, Student's <i>t</i>-test, No AuNPs <i>vs</i>. 5-nm AuNPs; N.S., no significance.</p

Effects of intracellular treatment with 5- or 40-nm AuNPs on spontaneous firing and excitatory synaptic transmission.

<p>(A) The representative traces of spontaneous firing from AuNP-treated and non-treated (No AuNPs) hippocampal CA1 neurons. (B) AuNPs of both sizes significantly increased the rate of spontaneous firing. (C) Neurons treated with 5-nm AuNP showed similar mEPSC frequency and amplitude to non-treated neurons. **<i>p</i><0.01, Student's <i>t</i>-test, No AuNPs <i>vs</i>. 40-nm AuNPs; ^##<i>p</i><0.01, Student's <i>t</i>-test, No AuNPs <i>vs</i>. 5-nm AuNPs; N.S., no significance.</p

Odds ratio of the HRV features between the CONT and DM with complications groups.

<p>Odds ratio of the HRV features between the CONT and DM with complications groups.</p

HRV feature correlations with age for the 8 T2DM groups.

<p>HRV feature correlations with age for the 8 T2DM groups.</p

Deriving probability and histogram from RR intervals.

<p>RR interval data from a CONT patient (a) and a DPNn patient (b), their PI (c,d) and PI histogram (e,f).</p