# Nanoformulation of Peptides for Pharmaceutical Applications: In Vitro and In Vivo Perspectives
## 5 In Vivo Analysis of Nanoformulated Peptides
The in vivo pharmacodynamic analysis showed that the inhibition of a tumor by the peptide-decorated nanoparticles was high, compared to free nanoparticles (79.92%). The apoptosis of tumor cells was shown to be induced after the treatment of the peptide-decorated nanoparticles, which indicates that the peptide effectively helps in targeting the tumor cells to control their growth. The histopathological analysis results revealed that there was no toxicity on normal tissues or the organs of the mice model treated with the peptide containing the nanoparticle [129]. Further, [PERSON] et al. (2015) introduced tLyP-1-functionalized nanoparticles into the mice model to evaluate their antitumor properties. The peptide-functionalized nanoparticle was injected though the tail vein of the animal models for equal distribution throughout their bodies. TLyP-1-functionalized tLPTS/HATS nanoparticles were identified to be completely penetrable into the tumor tissues and reduced the accumulation of nanoparticles in the liver, spleen, and kidney. The growth of the tumor was suppressed at around 74%, compared to standalone nanoparticles. Additionally, the study demonstrated that the lipid-loaded nanoparticles did not exhibit a loss of net body weight, indicating its nontoxicity. However, the cell apoptosis rate increased after the incorporation of peptide-functionalized nanoparticles [130]. Furthermore, [PERSON] et al. (2012) prepared the OA02 peptide encapsulated in micellar nanoparticles for cancer treatment by releasing the peptide against the a-3 integrin, which is overexpressed in ovarian cancer. In vivo bio distribution studies showed that the peptide-loaded nanoparticles possess the ability to target tumor sites faster than unloaded nanoparticles. Moreover, the peptide-coated nanoparticles were identified to penetrate deeper into the ovarian cancer cells and bind with the a-3 integrin to exhibit enhanced cancer cell inhibition [131]. Moreover, [PERSON] et al. (2017) synthesized a novel cyclic Arg-Gly-Asp (cRGD) peptide and coated it on the surface of cisplatin-loaded micellar nanoparticles to target the SAS-L1-Luc cells, which were inoculated onto the mice tongues. An in vivo antitumor analysis showed that there was no distinct weight loss in the peptide-encapsulated nanoparticle-treated mice and it has a high capacity to inhibit tumor growth. Moreover, the cRGD nanoparticles were identified to be rapidly accumulating on the tumor sites and interacting with \(\alpha\)v\(\beta\)3 integrins to be expressed in the endothelial cancer cells [132]. [PERSON] and co-workers (2017) developed a micelle nanoparticle (below 50 nm) using the cyclic RGD peptide cross-linked with poly(ethylene glycol)-b-poly(e-caprolactone) (PEG-PCL) to target glioma cancer. In vivo results indicated that cRGD-RCCMs had the potential to inhibit tumor growth and their efficiencies were enhanced by increasing the concentration of cRGD. No weight loss was identified in cRGD-RCCM-treated mice and their survival time prolonged. However, slight toxicities was observed in the liver, spleen, and kidney due to an increment in the cRGD concentration [133]. Moreover, [PERSON] et al. (2016) prepared carmustine-loaded polymeric nanoparticles using the T7 peptide, encapsulated on the surfaces of loaded micelles for targeting the tumor cells in the central nervous system. The results indicate that the T7 peptide-encapsulated nanoparticles possess enhanced abilities to highly accumulate in the tumor cells and penetrate deeper into brain tumors. Moreover, T7 peptides have been identified to potentially target Tf receptors, which could be overexpressed in the blood-brain barrier. In this study, luciferin was injected into the tumor and it has been identified that the intensity of the luminescence decreased due to the inhibition of the tumor cell growth. Weight was not observed in the animal model,compared to the uncoated T7 peptide-polymeric nanoparticles, with the longest survival time of the peptide.