**3.2 Artificial implant scopes**

Nanomaterials portray their chosen probability and thrusted promise in the field of regenerative medicine due to their extraneous physical/chemical properties. In general, the rejected implant materials which may be the cause for post administration implant pain and in order to avoid such rejection, nanotubes were attached to amino acids and to proteins, thereby achieved a promising development. Both the single and multiwalled forms can be effectively utilized as implants which may be either artificial joints or else other implant materials without any kind of host rejection output response. Perhaps, due to its unique material properties such as maximum tensile strength, these can effectively act as implant materials for bone substitutes and if suitably filled with calcium, such implants can be shaped or arranged within the bone structure [50, 51].

It has also been invented that proliferation and cellular adhesion can increase with the availability of SW and MW carbon nanotube composites and hence, these can be essentially integrated into natural nanomaterials and synthetic type materials to fabricate suitable nanocomposites. The specific type of CNT accustomed to artificial implants was represented in **Table 2**.

#### **3.3 Tissue engineering**

The scope of tissue engineering lies in the substitution of damaged tissue using biological alternatives that can possibly replace/repair original and normal


#### **Table 2.**

*Nature of CNT in artificial implants application.*

function. The recent advances in the emerging fields of material science have been promisingly supported in the growth of tissue engineering and regenerative medicine [54].

CNTs can be recommended for use in the field of tissue engineering under four different perspectives. They are cell tracking/labeling, sensing cellular nature and mechanism, augmenting the mechanism and enhancing the tissue matrices. Cell tracking/labeling is the specific capacity to identify implanted cell structures and to record the noteworthy improvement of tissue growth in vivo as well noninvasively [52]. Labeling of transferred cells by implants not only permits the evaluation of engineered tissue viability but also promotes a deep understanding of migration, bio-distribution, movement pathways and relocation of implanted cells. The non-invasive techniques nowadays become more familiar than traditional techniques such as cytometry owing to more time consumption and practical challenges associated with handling of usage. Hence, CNTs can be more feasible as contrast imaging agents for optical resolution, magnetic resonance behavior and also for radio tracer simulating models [54].

One of the prominent applications of CNTs in the study of tissue engineering is its ability to bio-distribution measurement and also it can be systematically varied using radiotracers applicable to gamma scintigraphy. The proper design of engineered tissue structures enhances and promotes monitoring of cellular physiology that includes protein/metabolite secretion rate, enzyme and other cofactor interactions, cellular growth/mechanism and molecules/ions transport. Novel nanosensors will be effectively utilized in such a way to determine continuous monitoring associated towards the working performance of engineered tissues.

Numerous and popular features involved in the structure of CNTs envisage them to become key elements for nanosensing devices owing to its maximum surface area and DNA or protein immobilizing capacity along with electrical properties [53].

Moreover, these carbon nanotubes possess distinctive electronic structures make the invention of redox active proteins and also amino acids thereby rendering the cell monitoring activity in engineered tissue patterns. In another research, MWNTs were combined with that of platinum micro nanoparticles and also able to identify thiols such as prescribed amino acids which include glutathione and L-cysteine observations in rat.

The cell matrix predominates its function in tissue engineering. Even though, PLA and PLGA have been utilized for tissue engineering, they tend to adopt the inbuilt mechanical strength and cannot be just functionalized pertaining to controversial version of synthetic polymer compounds. Hence, CNTs have potential applications as tissue scaffolds and able to ascertain the structural reinforcement. The only demerit of CNTs is such that they are not biodegradable. When CNTs are dissolved in certain quantity of polymeric substance, rapid enhancement in mechanical strength has been promptly noted. If these MWNTs combine with chitosan material it may lead to advancement in properties whereas SWNT on blending with natural collagen improves the cell growth of smooth muscles [43].

#### **3.4 Cancer cells tracing**

Nanodevices have been investigated that has the effective potential to generate new techniques in cancer treatment, diagnosis as well as detection. The geometric structures of these nanomaterials may be very small (< 100 nm) such that the body will evacuate it rapidly so as to become more efficient either through detection or by imaging and thereby enter the damaged cells and organelles inside the body to have interaction with DNA or protein molecules. The possible detection of cervical cancer causing cells among human beings can be improved by carrying out modification on the graphene electrode using peptide form of nanotube folic acid [55].

**41**

*Carbon Nanotubes: Synthesis, Properties and Applications*

As large quantity of cancer types is truly asymptotic throughout their initial stage and also due to absence of specific morphologic modifications among most of the neoplastic disorders in preliminary stage, possibly traditional cancer imaging and clinical methods such as X-ray, CT scan and even MRI scan does not require any kind of spatial resolution for such disease detection in initial stages. Imaging analysis using single walled CNTs have been explored for the past few decades. Coupling of radioisotopes with single walled CNTs along with imaging techniques based on radio nucleotides can progress advancement in tissue sensitivity, penetration as well

Many sophisticated protein biomarkers are available which are often overexpressed in the interior of cancer cells and they offer an entry mark for preliminary diagnosis, maintaining surveillance, prognosis, curative surgery techniques, advancement in disease monitoring therapy and finally detecting therapeutic response. Special categories of tumor biomarkers have been tremendously applied and also conceivably utilized in diagnosis and treatment of hepatocellular carcinoma, pancreatic, colorectal cancer, prostate cancer, ovarian tumor on epithelial cells which includes CA19-9 (carbohydrate antigen), carcinoembryonic antigen (CEA), alpha fetoprotein (AFP), human chorionic gonadotropin (hCG), carcinoma

There are various interim obstacles associated with conventional application and administration of chemo-therapic agents which includes system toxicity, lack of proper sensitivity/selectivity, minimum solubility, poor cellular distribution, lagging of certain clinical procedures, and inefficiency of specific drugs to overcome the cellular barriers for achieving the treatment of multidrug resistive cancer disease. Scientists and research experts have conceptualized various drug handling/ delivery systems to combat these terrific issues using silica nanomaterials, quantum dots, polymeric materials, dendrimers, liposomes, emulsions, micelles and even

As discussed above **Table 3**, CNTs possess specific features such as ultrapure/ maximum surface distribution, which essentially provoke them to act as a promising tool for drug delivery, nucleic acids and peptides. The selective drug or desired gene can be effectively coupled with tips and walls of carbon nanotubes and can easily trace out specific cancer causing receptors that are available on the cell structure and thereby such CNTs can even over cross the cell membrane of mammals through the mechanism of endocytosis or other plausible procedures. Thus, it can recognize the therapeutic drugs/genes much more reliably and safely in the affected

Recent discoveries of research experts paved the way to invent novel and efficient single walled CNT based drug delivery tool for targeting tumor which comprises of targeting ligands for tumor, drugs for anticancer treatment and also functionalized single walled CNTs. If such system has an interaction with cancer causing cells, it can provoke the receptor assisted endocytosis by identifying specific receptors to cancer cells onto the affected cell surface and perhaps specifically and efficiently release the active chemotherapeutic agents [58]. The release of drugs

In cardiology field, the CNTs are used for artificial valves to heart blocks, pacemakers, etc. These CNTs may be involved either as individual or in combined

antigen 125 (CA125) and specific antigen to prostate (PSA) [27].

cells that are reluctantly inaccessible during previous procedures.

*DOI: http://dx.doi.org/10.5772/intechopen.92995*

as nano medium spatial resolution.

**3.5 Gene and drug delivery applications**

molecular conjugates [56, 57].

using CNTs were highlighted in **Table 3**.

**3.6 Sensor-based biomedical applications**

*Carbon Nanotubes: Synthesis, Properties and Applications DOI: http://dx.doi.org/10.5772/intechopen.92995*

*21st Century Surface Science - a Handbook*

medicine [54].

observations in rat.

**3.4 Cancer cells tracing**

function. The recent advances in the emerging fields of material science have been promisingly supported in the growth of tissue engineering and regenerative

CNTs can be recommended for use in the field of tissue engineering under four different perspectives. They are cell tracking/labeling, sensing cellular nature and mechanism, augmenting the mechanism and enhancing the tissue matrices. Cell tracking/labeling is the specific capacity to identify implanted cell structures and to record the noteworthy improvement of tissue growth in vivo as well noninvasively [52]. Labeling of transferred cells by implants not only permits the evaluation of engineered tissue viability but also promotes a deep understanding of migration, bio-distribution, movement pathways and relocation of implanted cells. The non-invasive techniques nowadays become more familiar than traditional techniques such as cytometry owing to more time consumption and practical challenges associated with handling of usage. Hence, CNTs can be more feasible as contrast imaging agents for optical resolution, magnetic resonance behavior and also for radio tracer simulating models [54].

One of the prominent applications of CNTs in the study of tissue engineering is its ability to bio-distribution measurement and also it can be systematically varied using radiotracers applicable to gamma scintigraphy. The proper design of engineered tissue structures enhances and promotes monitoring of cellular physiology that includes protein/metabolite secretion rate, enzyme and other cofactor interactions, cellular growth/mechanism and molecules/ions transport. Novel nanosensors will be effectively utilized in such a way to determine continuous monitoring

Numerous and popular features involved in the structure of CNTs envisage them to become key elements for nanosensing devices owing to its maximum surface area and DNA or protein immobilizing capacity along with electrical properties [53].

Moreover, these carbon nanotubes possess distinctive electronic structures make the invention of redox active proteins and also amino acids thereby rendering the cell monitoring activity in engineered tissue patterns. In another research, MWNTs were combined with that of platinum micro nanoparticles and also able to identify thiols such as prescribed amino acids which include glutathione and L-cysteine

The cell matrix predominates its function in tissue engineering. Even though, PLA and PLGA have been utilized for tissue engineering, they tend to adopt the inbuilt mechanical strength and cannot be just functionalized pertaining to controversial version of synthetic polymer compounds. Hence, CNTs have potential applications as tissue scaffolds and able to ascertain the structural reinforcement. The only demerit of CNTs is such that they are not biodegradable. When CNTs are dissolved in certain quantity of polymeric substance, rapid enhancement in mechanical strength has been promptly noted. If these MWNTs combine with chitosan material it may lead to advancement in properties whereas SWNT on blending with natural collagen improves the cell growth of smooth muscles [43].

Nanodevices have been investigated that has the effective potential to generate new techniques in cancer treatment, diagnosis as well as detection. The geometric structures of these nanomaterials may be very small (< 100 nm) such that the body will evacuate it rapidly so as to become more efficient either through detection or by imaging and thereby enter the damaged cells and organelles inside the body to have interaction with DNA or protein molecules. The possible detection of cervical cancer causing cells among human beings can be improved by carrying out modification on the graphene electrode using peptide form of nanotube folic acid [55].

associated towards the working performance of engineered tissues.

**40**

As large quantity of cancer types is truly asymptotic throughout their initial stage and also due to absence of specific morphologic modifications among most of the neoplastic disorders in preliminary stage, possibly traditional cancer imaging and clinical methods such as X-ray, CT scan and even MRI scan does not require any kind of spatial resolution for such disease detection in initial stages. Imaging analysis using single walled CNTs have been explored for the past few decades. Coupling of radioisotopes with single walled CNTs along with imaging techniques based on radio nucleotides can progress advancement in tissue sensitivity, penetration as well as nano medium spatial resolution.

Many sophisticated protein biomarkers are available which are often overexpressed in the interior of cancer cells and they offer an entry mark for preliminary diagnosis, maintaining surveillance, prognosis, curative surgery techniques, advancement in disease monitoring therapy and finally detecting therapeutic response. Special categories of tumor biomarkers have been tremendously applied and also conceivably utilized in diagnosis and treatment of hepatocellular carcinoma, pancreatic, colorectal cancer, prostate cancer, ovarian tumor on epithelial cells which includes CA19-9 (carbohydrate antigen), carcinoembryonic antigen (CEA), alpha fetoprotein (AFP), human chorionic gonadotropin (hCG), carcinoma antigen 125 (CA125) and specific antigen to prostate (PSA) [27].

#### **3.5 Gene and drug delivery applications**

There are various interim obstacles associated with conventional application and administration of chemo-therapic agents which includes system toxicity, lack of proper sensitivity/selectivity, minimum solubility, poor cellular distribution, lagging of certain clinical procedures, and inefficiency of specific drugs to overcome the cellular barriers for achieving the treatment of multidrug resistive cancer disease. Scientists and research experts have conceptualized various drug handling/ delivery systems to combat these terrific issues using silica nanomaterials, quantum dots, polymeric materials, dendrimers, liposomes, emulsions, micelles and even molecular conjugates [56, 57].

As discussed above **Table 3**, CNTs possess specific features such as ultrapure/ maximum surface distribution, which essentially provoke them to act as a promising tool for drug delivery, nucleic acids and peptides. The selective drug or desired gene can be effectively coupled with tips and walls of carbon nanotubes and can easily trace out specific cancer causing receptors that are available on the cell structure and thereby such CNTs can even over cross the cell membrane of mammals through the mechanism of endocytosis or other plausible procedures. Thus, it can recognize the therapeutic drugs/genes much more reliably and safely in the affected cells that are reluctantly inaccessible during previous procedures.

Recent discoveries of research experts paved the way to invent novel and efficient single walled CNT based drug delivery tool for targeting tumor which comprises of targeting ligands for tumor, drugs for anticancer treatment and also functionalized single walled CNTs. If such system has an interaction with cancer causing cells, it can provoke the receptor assisted endocytosis by identifying specific receptors to cancer cells onto the affected cell surface and perhaps specifically and efficiently release the active chemotherapeutic agents [58]. The release of drugs using CNTs were highlighted in **Table 3**.

#### **3.6 Sensor-based biomedical applications**

In cardiology field, the CNTs are used for artificial valves to heart blocks, pacemakers, etc. These CNTs may be involved either as individual or in combined form to synthesize smart sensors and various multi-functional materials. They possess maximum aspect ratios that make the CNT to be extremely ideal for operating longer duration and of course continuous sensing. Their greater surface distribution shall be definitely exploited for providing material deposition in order to generate hybrid variety of functional materials or better functionalized to formulate different electrodes for certain applications [59].

CNTs are much prone to promote its ballistic conductivity which may occur owing to minimum scattering of electrons in their one dimensional solid structure containing mean free paths in the measurable range of tens to microns. The exerted mechanical stress/strain can even aid few reproducible changes acquainted with the electrical properties involved in CNT fibers, thereby felicitating it extremely viable to act as electro mechanical sensor devices. The occluded changes are noted as capacitance, inductance and electric resistance which can be directly correlated to the impact of strain **Figure 8**. Moreover, such CNTs are hugely responsive to compressive, flexural, tensile /torsional strain [60, 61].

The working mechanism of sensors derived from a simple CNT macroscopic assembly inculcate the change of their electrical resistance or resistivity resulting from mechanical strain is said to be piezo-resistivity, change of its inductance/ capacitance via mechanical strain, variation of its electrical resistivity with a


#### **Table 3.**

*Release of drugs from CNTs.*

**43**

**Author details**

**4. Conclusion**

Chennai, India

Aravind Kumar Jagadeesan1

Technology, Chennai, India

\*, Krithiga Thangavelu2

1 Department of Chemical Engineering, Sathyabama Institute of Science and

2 Department of Chemistry, Sathyabama Institute of Science and Technology,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: arvindhjsbu@gmail.com

provided the original work is properly cited.

sensitivity to different species and other toxic gases.

and Venkatesan Dhananjeyan1

*Carbon Nanotubes: Synthesis, Properties and Applications*

varying magnetic field is known as magnetoresistance [62].

type, pressure sensor devices, chemical sensors, and even mass sensors.

plausible variation with temperature is said to be thermo resistivity and a magnetoresistance may result due to variation in electrical resistance which may be due to

Even electrical resistance change can occur owing to variation in mechanical resonance frequency thereby resulting change in temperature, mass, pressure and strain. In contrast, the simultaneous change in electrical conductance/resistance is most predominant than any other mild variation accustomed in electrical properties. This happens partially due to selective and simple separation of charge carriers under the influence of temporary/permanent deformation which may lead to certain elevation in resistance. For every minute strain effects, the deformation is shown to be extremely elastic and the electrically conductive mechanism can be completely withdrawn due to its associated strain removal and thereby leads to a deduction in resistance [63]. However, plastic deformation has been proved to be much different. Though the resistance approaches zero due to strain removal and hence hysteresis curve has been fully observed. The various sensors involved with such CNT fiber yawns were strain

Nanomaterials provide an enriched knowledge on distinct probability and also definitely sound well in biomedical regenerative therapy for its uniqueness owing to its excellent physical as well as chemical properties. Thus, CNT both in modified and purified type have a definite potential of establishing promising applications in wide sectors of scientific fields. Perhaps, the prompt impregnation of other substituents in carbon nanoforms would confirm its strong perspective for their enhancing biomedical applications and in general medicine. Still then, there exist questions on unsolved issues whereas proximate homogeneity of the selected nanomaterial contains extensive distribution of nanotubes radius, unlike its geometric structures, classification of nanotubes, trace inclusion of residual elements, and a marked

*DOI: http://dx.doi.org/10.5772/intechopen.92995*

**Figure 8.** *Nanosensor schematic representation.*

#### *Carbon Nanotubes: Synthesis, Properties and Applications DOI: http://dx.doi.org/10.5772/intechopen.92995*

plausible variation with temperature is said to be thermo resistivity and a magnetoresistance may result due to variation in electrical resistance which may be due to varying magnetic field is known as magnetoresistance [62].

Even electrical resistance change can occur owing to variation in mechanical resonance frequency thereby resulting change in temperature, mass, pressure and strain. In contrast, the simultaneous change in electrical conductance/resistance is most predominant than any other mild variation accustomed in electrical properties. This happens partially due to selective and simple separation of charge carriers under the influence of temporary/permanent deformation which may lead to certain elevation in resistance. For every minute strain effects, the deformation is shown to be extremely elastic and the electrically conductive mechanism can be completely withdrawn due to its associated strain removal and thereby leads to a deduction in resistance [63]. However, plastic deformation has been proved to be much different. Though the resistance approaches zero due to strain removal and hence hysteresis curve has been fully observed. The various sensors involved with such CNT fiber yawns were strain type, pressure sensor devices, chemical sensors, and even mass sensors.
