**3.3 Poly(D,L-lactide-co-glycolide) (PLGA)**

The next nanocarrier that has been considered for sustained and targeted delivery of different agents is poly[L-lactide-co-glycolide] (PLGA)-based nanoparticles. Although PLGA have been applied many years ago, but the task of nanoparticles in mechanism of intercellular uptake, their trafficking, and sorting into different intercellular compartments, as well as their procedure of action for therapeutic efficacy of nanoparticles encapsulated agent at cellular level is recently considered [30] (**Figure 7**).

In addition, we know that the PLGA nanoparticles have deeper in vitro and in vivo effects in comparison with industrial nanoparticles in similar range such as ferrous oxide and zinc oxide. The effect of PLGA nanoparticles on cell viability was characterized by in vitro cytotoxicity analysis via a WST assay. The PLGA, silica, and ferrous oxide have a cell viability up to 75%, but for zinc oxide, particles cell viability significantly reduced [31]. The researchers found that nanoparticle mean size correlates linearly with polymer concentration is between 70 and 250 nm [32].

The PLGA/MWCNT composite was considered as a scaffold material to treat artificial bloods. PLGA/MWCNT nanocomposite is prepared using electrostatic technique, in which layers of MWCNTs are deposited on the PLGA. For in vivo and in vitro analysis, the fibrinogen is immobilized on PLGA/MWCNT composite and incubated in non-stimulated platelet-rich plasma (PRP) for platelet studies. The interaction of fibrinogen and PRP, are characterized on the prepared PLGA/ MWCNT nanocomposite [33].
