Design, synthesis and evaluation of DNA nano-cubes as a core material protected by the alginate coating for oral administration of anti-diabetic drug

Abstract

Poor control towards glycemic levels among diabetic patients may lead to severe micro/ macro-vascular and neuropathic complexities. Proper functioning of alpha-beta cells of pancreases is required to attain long term glycemic control among type 2 diabetics. The recent developments to manage diabetes are focused on controlling the insulin-glucagon secretions from the pancreases. DPP-4 inhibitors class of drugs after elevating GLP-1/GIP (incretins) levels in the blood, not only raise the insulin levels but also suppress the glucagon level. Vildagliptin (VI) is a potent DPP-4 inhibitor with least adverse events compared to other DPP-4 inhibitors. We encapsulated VI into 3D nanocube that gets bind to the DNA due to secondary amine in its chemical structure. DNA-nanocube being negatively charged was incubated with the PLL to attain positive surface. Ultimately VI loaded nanocubes were coated with the negatively charged Na-alginate via electrostatic attraction method to get stable spherical nanospheres for oral delivery of VI. Nanospheres were evaluated physically through native PAGE analysis, DSC, TGA, dissolution testing, XRD and FTIR. We attained uniformed and spherical nanospheres with stable topology, nanoscale size precision (40–150 nm in diameter), Entrapment efficiency (up to 90%), prolonged drug release (13 ± 4 h) at basic pH, and superior oral antidiabetic effects with improved GLP1 and glycemic levels. The formulated nanospheres attained size uniformity and better therapeutic outcomes in terms of reduced adverse events and better control of glycemic levels than previously reported methods with decreased dosage frequency tested in Db/Db mice.

The effective transfection of a low dose of negatively charged drug-loaded DNA-nanocarriers into cancer cells via scavenger receptors

“…The shifts confirmed the loading of CPT onto DNA-NWs in the UV peaks of the DNA (260–300 nm), CPT (280 nm), and the FITC dye (500–520 nm) that was tagged to the CPT for loading [ 22 ], as shown in Fig. 3 B.…”

“…Scaffold strands were circularized, as previously reported [ 22 ]. Briefly, a 5′-phosphorylated 50 μM linear scaffold (84-NT) was annealed with a 60 μM splint strand (20-NT) such that it was folded to join its two ends together with the help of splint strand [ 23 ].…”

“…After joining the two ends of the scaffold strand with the help of splint strands, the two ends of the scaffold strand were covalently joined together via the ligation process using T4 DNA-ligase (8 μL, 350U/μL) at 16 °C for 16 h in the presence of freshly prepared TE buffer [ 25 ]. The ligating enzyme was heat-denatured, followed by exonuclease-1 treatment (8 μL, 5U/μL) for 35 min while incubating at 37 °C to digest and eliminate linear strands [ 22 ]. After that, exonuclease-1 was heat-denatured.…”

“…The unbound CPT-FITC was estimated spectrophotometrically using a Nanodrop-2000c (Thermo Fisher Scientific, USA) from the supernatant mixture using Eq. (1) [ 22 ]. …”

Development and functionalization of DNA nanostructures for biomedical applications

“…Using a diabetic Db‐Db mice model, superior control of glycemic levels was demonstrated with this DNA‐nanoconjugates. This was then shown to be attributed to the sustained inhibition of dipeptidyl peptidase‐4 (DPP‐4) in the intestine and blood, causing elevation of the levels of incretin peptides, including glucagon‐like peptide 1 (GLP1) and glucose‐dependent insulinotropic polypeptide (GIP) 42,43 . Hybrid nanoparticles fabricated from conjugating multiple polymer coatings over DNA‐nanocubes showed prolonged vildagliptin release and superior control of glycemic levels than the control group of diabetic mice 44,45 .…”