**2. Compatibility of nanomaterials towards biological interactions**

NMs attract considerable interest due to their unique, tunable, versatile physicochemical properties, easy preparation methods, biocompatibility, and surface functionalization [1]. Nonetheless, the compatibility of the nanoparticles with biological entities constitutes the most fundamental phenomenon and highlights the importance of basic research [9]. Most bio-applications, including drug delivery, bioimaging, and treatment, start from the attachment of nanoparticles onto the target cells. The biocompatibility of nanoparticles depends on the physical and chemical attributes like diameter, shape, composition, concentration, functionalized moieties, and surface potential (**Figure 1**) [10]. Among the various NMs, Quantum dots have risen as an innovative bio-imaging tool due to their unique tunable physicochemical attributes. Existing research has guided the development of versatile quantum dots that are highly fluorescent and stable under diverse biological circumstances. Moreover, quantum dots with enclosed amphipathic polymers have been developed and surface-functionalized with receptor targeting ligands for bio-imaging and drugdelivery in animal models. Fascinatingly, these materials were found to be compatible with the cells. However, their complete chronic *in vivo* genotoxicity, blood, and organ compatibility need to be assessed [1, 7, 11].

Polymeric nanoparticles have drawn considerable attention in drug and gene delivery, tissue engineering, and many biomedical applications due to their non-toxic nature and high compatibility to biological systems. They are colloidal in nature and composed of natural or synthetic, or semi-synthetic polymers. In this perspective, biodegradable nanoparticles of the highly compatible triblock copolymer are used for non-viral gene transfections [3].

Liposomes are another popular nanomaterial drug delivery system that is best documented and adapted owing to their bio-congenial physicochemical properties [12]. Liposomes consist of unilamellar/ multilamellar lipid bilayers having an aqueous core inside. The nanoscale carrier system offers substantial advantages such as

#### **Figure 1.**

*Precision of targeted drug delivery using nanocarriers and bio-compatibility. Nanoparticle based drug delivery platform depends on surface functionality, size and shape and surface charge and composition.*

## *Nanotechnology Application and Intellectual Property Right Prospects of Mammalian Cell... DOI: http://dx.doi.org/10.5772/intechopen.99146*

biodegradability, biocompatibility, ease of synthesis, less toxicity, sustained drug release, and the ability to incorporate hydrophilic and hydrophobic drugs. Liposomalsurface modification is a crucial strategy for targeted therapy and especially for cancer treatment [13]. Seventeen liposomal formulations are clinically approved for cancer, inflammation, infectious diseases, antibiotic drugs, and anesthetics, while several liposomal formulations are under various phases of clinical trials [12, 13].

Despite several encouraging biomedical implementations of nanoparticles, the biocompatible assessments including, complete acute and chronic toxicological evaluation of NMs, are inadequately comprehended. Additionally, the toxicity of the nanoparticle design aims to find out favorable physicochemical attributes of different materials. Hence, the active bio-molecule with biological entities must be highly allied to the nanoparticles approaching direct contact with biological objects rather than its transient initial distribution. Much to our intrigue, various nanoparticles - liposomes, lipoplexes, polymeric nanoparticles, polyplexes, metal nanoparticles, metal oxides, dendrimers, and quantum dots are wisely engineered for their medical application like diagnosis, drug and gene delivery, tissue engineering, and biosensing [8, 13, 14]. Moreover, it is unavoidable to thoroughly assess and investigate compatibility/unwanted toxicity with nanoparticles to bring clinical success. The subsequent section will relate to how the physicochemical properties of engineered nanoparticles can be persuaded towards accomplishing the desired biological aspiration lacking any toxicological impact.
