**6. Preparation of polymer nanoparticles**

There are several approaches to prepare and synthesize the polymeric nanoparticles such as (a) desolvation, (b) emulsification, (c) esterification, (d) thermal gelation, (e) nanospray drying, (f) self-assembly, etc. Apart from these approaches, there are mainly two polymerization methods widely followed for the preparation of polymer nanoparticles such as (1) addition polymerization and (2) condensation polymerization. The preparation of polymer nanoparticles is not an easy task. The size and shape of the particle are a very important concern while preparing the polymer-based nanoparticles. As the number of monomers or polymer units increases, the size of the nanoparticle or capsule also increases. It is easy to prepare and reproduce the polymeric nanoparticles with the porous matrix for loading the drug molecules, but its size and shape cannot be formulated easily. Amino and carboxyl functional groups permit functionalization and surface modifications, but patterning them in a fruitful design is a challenging task, and it can overcome through the detailed study of their properties [52]. However, albumin is phase separated due to reduced water solubility followed by the formation of the tiny particles

**149**

**Figure 6.**

*Polymer Properties: Functionalization and Surface Modified Nanoparticles*

such as coacervates which has a tendency to dissolve again and again with universal solvent. Albumin functional groups are cross-linked by agents like glutaraldehyde, and this cross-linking is achieved through the lysine and arginine amino groups which are present in the so-called amino acids. The stability of these cross-linked nanoparticles also affects the surface properties of the nanoparticles. Furthermore, separation methods, stirring methods, time, temperature, ultrasound, magnetic effect, sonication time, and bath temperature also show an adverse effect on the

*Pictorial representation of different types of polymer nanoparticles. Image (a) core-shell nanoparticle, (b) liposomal nanoparticle, (c) star-shaped NPs, (d) dendritic nanoparticles, (e) coral reef-type nanoparticle, and* 

There are significant advantages with the aforementioned approaches to prepare the polymer nanoparticles, emulsification technique requires removal of organic solvents and surfactants, thermal stabilization method is applicable to heat-stable molecules, chemical stabilization is needed to remove the toxicity of cross-linkers and uncontrolled linking, desolvation leads to the substitution for the emulsification and reproducibility with safe and suitable properties for the preparation of polymeric nanoparticles, and **Figure 6a–f** shows the morphology of different types

Variety of techniques used to find out the chemical formula and structural confirmations of polymers after synthesis, for example, nuclear magnetic reso-

and structure of the synthesized compound. Spectrophotometer fourier transform infrared (FTIR) for functional groups identification and it has been acquired through the absorption spectra followed by the analysis of peak positions, highresolution mass spectrometer (HRMS), and low-resolution mass spectrometer to measure the molecular weight of samples, and this technique give very much

H and 13C for functional groups, chemical formula,

*DOI: http://dx.doi.org/10.5772/intechopen.84424*

surface morphology of albumin nanoparticles.

*(f) symmetric pattern of nanoparticles [46–51, 53].*

**7. Characterizations of nanoparticles**

nance (NMR) followed by the 1

of nanoparticles designed for pictorial representation [54, 55].

*Polymer Properties: Functionalization and Surface Modified Nanoparticles DOI: http://dx.doi.org/10.5772/intechopen.84424*

**Figure 6.**

*Role of Novel Drug Delivery Vehicles in Nanobiomedicine*

the usage of biomedical applications [48]. In such cases the composite of polymer thin film embedded or doped with some other metal nanoparticles or organic and inorganic materials needs to be molded without changing its original activity or characteristic properties. However, the functional groups such as amide (–NH), amine (–NH2), acid (–COOH), aldehyde (–CHO), keto (–C=O), ester (R–COO–R), anhydride (R–CO–O–CO–R), acid halides, hydrogen halides, salts, and solvents (organic, inorganic) can also influence the surface properties for the nanoparticles or nanocapsules. Based on the requirement, it can be chosen to modify the particles surface and size, shape, etc. The concentration of the solvent also affects the pattern of the nanoparticles and nanocapsules. Sometimes additives like precursors and surfactants can also show an adverse effect on the morphology of polymer nanoparticles [49]. The activity (bioactive nature) of polymer nanoparticles and nanocapsules can disturb the body metabolism. The active functional groups with their potential resonance capabilities can also interact with body fluids and interfere to shore-up the mutations. Apart from the solvent, there are several factors which can affect the patterning of the surface of the nanoparticles such as pH, thermal stability, rubbery nature, solid (amorphous and crystalline) nature, environmental conditions, etc. The stability, biocompatibility, and route or synthesis methodology are also playing a vital role to tune up the surface properties of the polymeric nanoparticles and capsules. For example, (a) protein nanoparticles have stability issues during storage. If the storage conditions are not followed properly, they may get contaminated and become toxic [50]. But these protein-based NPs are very much compatible with their unique characteristic features such as nontoxic nature and nonantigenic nature. As per the existing literature, it is known that bulk protein in plasma can easily bind to a variety of drug molecules through its trajectory while carrying them to deliver target specifically. And these are very much flexible to ease scale-up manufacturing and other nanobiotechnological applications; (b) albuminbased nanoparticles are very much suitable for the morphological modifications and to tune the surface properties. These are biocompatible and biodegradable without any detrimental activities upon mankind usages. Sometimes these albumin-based nanoparticles are used for drug delivery and other biomedical applications.

However, protein albumin contains a huge number of charged amino acid residues, and it binds water-soluble drugs through charge interactions, and it leads to surface

There are several approaches to prepare and synthesize the polymeric nanoparticles such as (a) desolvation, (b) emulsification, (c) esterification, (d) thermal gelation, (e) nanospray drying, (f) self-assembly, etc. Apart from these approaches, there are mainly two polymerization methods widely followed for the preparation of polymer nanoparticles such as (1) addition polymerization and (2) condensation polymerization. The preparation of polymer nanoparticles is not an easy task. The size and shape of the particle are a very important concern while preparing the polymer-based nanoparticles. As the number of monomers or polymer units increases, the size of the nanoparticle or capsule also increases. It is easy to prepare and reproduce the polymeric nanoparticles with the porous matrix for loading the drug molecules, but its size and shape cannot be formulated easily. Amino and carboxyl functional groups permit functionalization and surface modifications, but patterning them in a fruitful design is a challenging task, and it can overcome through the detailed study of their properties [52]. However, albumin is phase separated due to reduced water solubility followed by the formation of the tiny particles

modifications and morphological changes [51].

**6. Preparation of polymer nanoparticles**

**148**

*Pictorial representation of different types of polymer nanoparticles. Image (a) core-shell nanoparticle, (b) liposomal nanoparticle, (c) star-shaped NPs, (d) dendritic nanoparticles, (e) coral reef-type nanoparticle, and (f) symmetric pattern of nanoparticles [46–51, 53].*

such as coacervates which has a tendency to dissolve again and again with universal solvent. Albumin functional groups are cross-linked by agents like glutaraldehyde, and this cross-linking is achieved through the lysine and arginine amino groups which are present in the so-called amino acids. The stability of these cross-linked nanoparticles also affects the surface properties of the nanoparticles. Furthermore, separation methods, stirring methods, time, temperature, ultrasound, magnetic effect, sonication time, and bath temperature also show an adverse effect on the surface morphology of albumin nanoparticles.

There are significant advantages with the aforementioned approaches to prepare the polymer nanoparticles, emulsification technique requires removal of organic solvents and surfactants, thermal stabilization method is applicable to heat-stable molecules, chemical stabilization is needed to remove the toxicity of cross-linkers and uncontrolled linking, desolvation leads to the substitution for the emulsification and reproducibility with safe and suitable properties for the preparation of polymeric nanoparticles, and **Figure 6a–f** shows the morphology of different types of nanoparticles designed for pictorial representation [54, 55].
