Effect of oil–water interface and payload-DNA interactions on payload-encapsulated DNA nanogels

Herein, we investigated the influence of emulsion process and DNA sequence on the morphology and surface property of the as-fabricated gel particles with and without payload. Nanogels can be prepared by using synthetic and kiwifruit-derived DNA above a certain concentration whilst nanocapsules can only be prepared by using a synthetic 19-mer DNA containing A nitrogen base. Kiwifruit-derived DNA was used to encapsulate two payloads, which were DOX and lipase, via oil-in-water and water-in-oil processes. The oil–water interface and payload-DNA interactions dictated their size, surface property, and payload encapsulation. The DOX-encapsulated nanogels exhibited comparable payload encapsulation regardless the emulsion process because DOX would not only intercalate in the DNA but also bind with the negatively charged DNA. The lipase-encapsulated nanogels prepared via oil-in-water process exhibited higher payload encapsulation and activity than those via water-in-oil process due to its hydrophobic nature and the creation of oil–water interface. Moreover, the advantage of enzyme encapsulation was revealed in the case at acidic solution pH. This study revealed the importance of the oil–water interface and payload-DNA interactions on the preparation of payload-encapsulated DNA nanogels.