Seite - 6 - in Cancer Nanotheranostics - What Have We Learnd So Far?

Condeetal. RecentAdvancesonCancerNanotheranostics substances within the body at a reduced risk in comparison to conventional therapies. At the present time, there is a growing need to enhance the capabilityof theranosticsprocedureswhere innovativemultifunctional nanocarriers for cancer theranostics may allow the development of diagnostics systems such as colorimetric and immunoassays, and in therapy approaches throughgenetherapy,drugdeliveryandtumortargetingsystems incancer (Condeetal., 2014). Some of the thousands and thousands of published nanosystems so far will most likely revolutionize our understanding of biologicalmechanisms and push forward the clinical practice through their integration in future diagnostics platforms. Nevertheless, despite the significant efforts toward the use of nanomaterials in biologically relevant research,more in vivo studies are needed to assess the applicability of these materialsasdeliveryagents. Infact,onlyafewhavegonethrough feasible clinical trials. Nanomaterials have to serve as the norm rather than an exception in the future conventional cancer treatments. Future in vivoworkwill need to carefully consider the correct choiceof chemicalmodifications to incorporate into the multifunctional nanocarriers to avoid activation off-target, sideeffectsandtoxicity. It is imperious to learn how advances in nanosystems’ capabilities are being used to identify new diagnostic and therapy apparatuses driving the development of personalized andprecisionmedicine in cancer therapy anddiagnostics; learn howincorporatingcancerresearchandnanotechnologycanhelp patient life quality; identify how to decipher nanotheranostics data intoarealclinical strategy;and, lastbutnot least, learnwhat methodsare showing fertile results in turningpromisingclinical data into treatmentrealities (Condeetal., 2014). Althoughall studiesdescribedinthisTopicprovideabaseline level of data in support of the effectiveness and safety of nanomaterials,wewonderwhathavewe learnedsofar? Current trends inbiomedicinehavebeen focused toward the useofnewmaterials capable toaddressparticularandindividual characteristics in strategies for molecular precision therapies. In this endeavor, nanoparticles have allowed a tremendous leap forward incombiningdiagnosticsandtherapy inasingle system and doing so at the nanoscale. Nanotheranostics have enabled the integration of targeting, imaging and therapeutics in a singleplatform,withprovenapplicabilityon themanagementof heterogeneousdiseases. Despite the plethora of proposed systems, only but a few products are currently includedclinical trials andmuchremains to be done to allow effective clinical translation of these promisingnanotheranosticsplatforms. Several nanoconjugates have been proposed, varying in material, size and shape; some bringing current therapeutic approaches to thenanometer scalewhileothers enactdisruptive properties only possible by combination of differentmolecules and chemistries at the nanoscale (Conde et al.). For example, achievingcontrolledcellularresponsesofnanoparticles iscritical for the successful development and translation of NP-based drug delivery systems. Conde et al. and Hong et al. (Pearson et al.) reportedacomplete surveyon themost important factors for careful design of nanoparticles and the demand for precise control over the physicochemical and biological properties of NPs. Liu et al. discuss the potential of star shaped nanoparticles in novel imaging approaches and strategies combining therapy and imaging in cancer. In fact, the potential of application of nanoconjugates in enhanced imaging strategies andplatforms is discussedbyAlcantara et al.withparticular emphasis in current trendsinmolecular imagingforoptimizedmanagementofbreast cancer. Theranostics of brain diseases such as brain cancer, is a daunting challenge due to the unique environment of central nervous system (Bhaskar et al., 2010). Yet passing the blood- brain barrier (BBB) is particularly difficult. The proper design of such engineered “nanocarriers” becomes very important in translocating the impermeable membranes of the brain to facilitate drug delivery. At the same time, it is also required to retain the drug stability and ensure that early degradation of drugs from the nanocarriers does not take place. In fact, Mahmoudi and Hadjipanayis reported a great opinion piece about the applicationofmagneticnanoparticles (MNPS) for the treatment of brain tumors and howMNPswill likely assume a larger role in brain cancer treatment in combinationwith other adjuvant therapies. Talking about other adjuvant therapies, radiation and gene therapyhavealsogainedmomentuminthe lastyearswhenusing nanomaterials for cancer therapy. Cooper et al. reported how radiation therapy is oneof themost commonlyused treatments forcancerandwhichdirections to followfor the futurebasedon current stateofnanoparticle-assistedradiationtherapy. Regardinggene therapy,MorenoandPegoreportedacritical overviewofusing therapeutic antisenseoligonucleotides against cancer and how difficult has been to get to the clinic. This is in fact not only a problem with gene therapy but a universal issue aswhilstmanypre-clinical datahas beengenerated, a lack of understanding still exists on how to efficiently tackle all the different challenges presented for cancer targeting in a clinical setting. Perhaps another interesting avenue in cancer nanotheranostics is the interfering effect of the immune system in the efficacy of proposed platforms. In fact, a clear perspective on the interaction between immune response and immune modulators is still missing from the general picture of nanotheranostics, not only in what concerns the organisms response to the systemic delivery of nanoconjugates that may hamper efficacy, but also the use of the immune response and nanoconjugates interaction with immune system as means to achievehigher andmoredirected/targeted therapy to thecancer site. As such, the effect and response of diverse properties of nanodiagnosticsplatforms in theorganismshavebeendiscussed by Clift et al. where nanoconjugates are discussed in terms of the immune response triggered after systemic delivery; whereasConniot et al. andPearsonetal. (Dawidczyketal.)have demonstrated how nanotheranostics may use and profit from thespecificandunspecific immuneresponse toenhanceefficacy. Actually, cancer immunotherapy is nowadays consider a hot topic andahugebreakthrough inmodernScience (Condeet al., 2015). Frontiers inChemistry |www.frontiersin.org January2016 |Volume3 |Article71 6|