PTEN and central nervous system cancer: Zamora et al. delivered the tumor suppressor gene phosphatase and tensin homolog (PTEN) and the cytosine deaminase (CD) pro-drug activating gene into photosensitizer (AlPcS2a)-treated U87 and U251 glioma cell monolayers and multicell tumor spheroids using polyamine protamine sulfate/Eosin 5-isocitrate conjugated polyplexes with acid degradable monomers polymerized into shelled nanoparticles, followed by a 670 nm laser at 5 mW/cm2 [135,136].