Nanomaterials: Versatile Drug Carriers for Nanomedicine
277
a trait required the most for tissue regeneration. The scaffolds are to be embedded
at the site of a target restricting its use [111]. According to another point of view,
the usage of hydrogels is more popular as they can be injected at the site of injury
and achieve the shape of the defect with extraordinarily elastic and flexible due to its
magnitude to retain water. In recent clinical trials, biodegradable gelatine hydrogel
was combined with rhFGF-2, injected into the knee of osteoarthritic patients during
the surgery resulting in safe and successful [112]. In another clinical trial, FGF was
used in fibrin hydrogel and was used in the treatment of cervical spinal cord injury,
revealing strong properties of nerve regeneration [113].
For the second-degree burns, the use of granulocyte-macrophage colonystimulating factor (GM-CSF) along with hydrogel was found to be active and safe
[114]. Even the dispensation of PDGF in a hydrogel with a periodontal defected
patient resulted in remarkable advancement in none regeneration [115]. The FDA
has approved the use of carboxymethylcellulose-PDGF based topical gel for the
treatment of diabetic neuropathic ulcers. Hydrogels used as drug delivery vehicles
have been studied in various preclinical researches showing positive outcomes in
the regeneration of several injured tissues. These hydrogels are loaded with growth
factors for implantations or as injectable solutions [116].
In some cases, a mixture of hydrogels containing growth factors is placed over
a scaffold and embedded at the site of injury. For example, hyaluronic acid/fibrin
hydrogel conjugated with bone morphogenetic protein-2 (BMP-2) exhibited an
activity of robust bone regeneration. Similarly, BMP-2 was delivered using heparin
hydrogel coated over the poly-lactide caprolactone scaffold, leading to active and
improved bone formation and mineralization [117]. Researchers used new covalent
binding strategies to avoid rupture of growth factors from the hydrogels, resulting in
improved properties of hydrogel consisting of sustained release of growth factor at
the targeted site.
17 Advanced Targeted Nanomedicine
The heterogeneity and adaptability of different ailments are strenuous to overcome,
which creates problem to have an ordinary cure based on passive or active drug
targeting. Therefore, it is foremost to consider the use of external physical stimuli as a
targeting strategy. The infected area varies from the healthy tissues in various physical
properties such as lack of oxygen, temperature, and pH, which can be exploited for
targeted strategies. The principle behind the physical targeting is the use of nanoparticles along with a physical stimulus applied externally, or it is originated at the
infected site. This prompts either a physical change in the nanoparticle structure,
causing target eradication or modulating the rate of release of the drug. Electromagnetic radiation, ultra-sound, mechanical forces, lack of oxygen, temperature, and pH
are various stimuli used for physical targeting.
277
a trait required the most for tissue regeneration. The scaffolds are to be embedded
at the site of a target restricting its use [111]. According to another point of view,
the usage of hydrogels is more popular as they can be injected at the site of injury
and achieve the shape of the defect with extraordinarily elastic and flexible due to its
magnitude to retain water. In recent clinical trials, biodegradable gelatine hydrogel
was combined with rhFGF-2, injected into the knee of osteoarthritic patients during
the surgery resulting in safe and successful [112]. In another clinical trial, FGF was
used in fibrin hydrogel and was used in the treatment of cervical spinal cord injury,
revealing strong properties of nerve regeneration [113].
For the second-degree burns, the use of granulocyte-macrophage colonystimulating factor (GM-CSF) along with hydrogel was found to be active and safe
[114]. Even the dispensation of PDGF in a hydrogel with a periodontal defected
patient resulted in remarkable advancement in none regeneration [115]. The FDA
has approved the use of carboxymethylcellulose-PDGF based topical gel for the
treatment of diabetic neuropathic ulcers. Hydrogels used as drug delivery vehicles
have been studied in various preclinical researches showing positive outcomes in
the regeneration of several injured tissues. These hydrogels are loaded with growth
factors for implantations or as injectable solutions [116].
In some cases, a mixture of hydrogels containing growth factors is placed over
a scaffold and embedded at the site of injury. For example, hyaluronic acid/fibrin
hydrogel conjugated with bone morphogenetic protein-2 (BMP-2) exhibited an
activity of robust bone regeneration. Similarly, BMP-2 was delivered using heparin
hydrogel coated over the poly-lactide caprolactone scaffold, leading to active and
improved bone formation and mineralization [117]. Researchers used new covalent
binding strategies to avoid rupture of growth factors from the hydrogels, resulting in
improved properties of hydrogel consisting of sustained release of growth factor at
the targeted site.
17 Advanced Targeted Nanomedicine
The heterogeneity and adaptability of different ailments are strenuous to overcome,
which creates problem to have an ordinary cure based on passive or active drug
targeting. Therefore, it is foremost to consider the use of external physical stimuli as a
targeting strategy. The infected area varies from the healthy tissues in various physical
properties such as lack of oxygen, temperature, and pH, which can be exploited for
targeted strategies. The principle behind the physical targeting is the use of nanoparticles along with a physical stimulus applied externally, or it is originated at the
infected site. This prompts either a physical change in the nanoparticle structure,
causing target eradication or modulating the rate of release of the drug. Electromagnetic radiation, ultra-sound, mechanical forces, lack of oxygen, temperature, and pH
are various stimuli used for physical targeting.