types of liposomes: the smaller one below 1  µm in size and consisting of 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), and the bigger oneup to 4  µm insize and consisting of phosphatidylethanolamine (PE) extractedfrom Escherichia coli (E. coli PE). They used a recombinant expression plas-mid of the nucleocapsid (Cap) protein coding gene of porcine circovirus type2 (PCV2), pORF2. A pORF2 dispersion was used to obtain the lipoplexwith the gene and transfect a porcine circovirus (PCV)-free PK-15 cell line.The expression of Cap protein was determined by Immunofluorescence Assayshowing that pORF2 gene was successfully delivered.

Polymersomes are structures based on the orientation of amphiphilicblock copolymers which are able to form a range of structures. The syn-thesis method is similar to that described for the production of biodegrad-able polymeric particles based on a double emulsion and solvent removal.As a result, a diblock copolymer membrane containing an aqueous corewith any hydrophilic is formed. These structures offer superior mechanicalproperties than those of lipid vesicles. The wide range of block copolymerchemistries available opens new possibilities to develop specific novel mem-branes. Different types of copolymers can be used; for example, Thiele etal. [187] worked with P2VP-PEO (poly-2-vinylpyridine-b-poly(ethylene ox-ide)) to produce polymerosomes with sizes from 40 nm up to 2  µm. Brown etal. [188] used the pH sensitive block copolymer PMPC25-b-PDPA70 (poly(2-(methacryloyloxy)ethyl phosphorylcholine)-poly(2-(diisopropylamino)ethyl methacry-late)) to encapsulate Bovine Serum Albumin (BSA) as a model protein. Theco-polymer remains in solution below pH 6.4 with nanostructures formedabove this value. By introducing basic solutions in the microfluidic devicewithin the correct pH range and at a correct flow rate, it is possible to causethe spontaneous self-assembly of polymersome nanostructures entrapping theactive compound inside. Authors pointed out that the production rate withthis device can be up to 3 times higher than that using the conventionalprocess with a similar BSA encapsulation efficiency.

Solid lipid nanoparticles (SLNs) can be prepared by several methods.Usually high pressure homogenization is preferred due to the fact it is an eas-ily scalable procedure, and it is possible to predict the final particle size [189].Nevertheless, emulsion-solvent evaporation processes are also employed. Themain potential application of SLNs is the delivery of poorly water-solubledrugs. Puerarin (8-glucosyldaidzein) is an isoflavone C-glycoside with com-prehensive pharmacological actions in the treatment of cardiovascular andcerebrovascular diseases, diabetes, and other diseases [190]. Puerarin-loaded

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