Biomedical Engineering Reference
In-Depth Information
drugs leads to therapeutic concentrations at the site of infection for short periods of time; therefore,
forced repeated doses over longer periods are required
[59]
. In contrast, the use of local delivery of
antibiotics specifically administered in the site of infection (periodontal pocket) could be very use-
ful in eliminating pathogens, and thus enhancing the effect of conventional surgical therapy without
the side effects of systemically administered antibiotics
[53,60]
.
In addition to the antiinfective therapy to prevent the progression of periodontal disease, it is
necessary to initiate a regenerative therapy to restore the structures destroyed by the disease
[61]
.
In 2006, Kong et al.
[2]
published a review focusing on the development of nanomaterials and their
potential use in the treatment of periodontal diseases, including diagnosis and treatment. Several
regenerative options have since then been developed to treat diverse causes of periodontal dis-
eases
[62]
. These include bone grafting, guided tissue regeneration, enamel matrix protein deriva-
tive, basic fibroblast growth factor, stem cell therapy, and photodynamic therapy (PDT)
[55,62]
.
Due to the advances in biotechnology, progress in recombinant protein technology, protein- and/or
gene based therapy, and tissue engineering has made it possible to use growth factors (GFs) and
polynucleotides as effective drugs for facilitating wound healing and tissue regeneration
[55]
.
Unquestionably, the localized delivery of GFs to the periodontium is an emerging and versatile
therapeutic approach with the potential to regenerate the periodontium and the bone
[63]
. The half-
lives of soluble GFs and other polynucleotides in the body are short because they are rapidly
degraded and are typically deactivated by enzymes. They are also susceptible to other chemical and
physical degradation reactions that occur in the body
[55,63]
. In order to preserve the GF bioactiv-
ity and control the GF release, several controlled release technologies are being explored, including
the delivery of GFs by means of micro- or nanoscale particles, prefabricated scaffolds,
injectable gels, composites, and so on. According to Chen et al.
[55]
, carriers and delivery systems
for GFs must be able to increase their retention at treatment sites for enough time to allow tissue
regenerating cells to migrate to the area of injury and to proliferate and differentiate and eliminate
loss of bioactivity. Furthermore, properties such as easy administration, targeted delivery, con-
trolled release kinetics, and cell/tissue permeation enhancement are desirable.
23.3.1
Polymeric nanoparticles
Polymeric materials have been widely investigated for drug-delivery devices and tissue engineering
[55]
. Nonbiodegradable as well as biodegradable polymers have been used for the preparation of
micro- and nanoparticles administered by the nasal, pulmonary, oral, or parenteral routes. These
materials include synthetic or natural polymers and modified natural substances
[7,53,59]
.
Biodegradable polymers, of natural or synthetic origin, have been widely used as drug-delivery sys-
tems for many bioactive compounds and are extensively employed in periodontal drug-delivery
devices because of their biocompatibility, since they can be degraded into acceptable biocompatible
products by chemical or enzymatic processes
[53,55]
. The devices manufactured with biodegradable
materials do not require removal at the end of the treatment.
A number of drug-delivery systems for the treatment of periodontal diseases are being designed
for targeted controlled drug release. Research has involved the use of local drug-delivery systems
based on micro- and nanoparticles made from biocompatible or biodegradable polymers.
A comprehensive review
[53]
has been recently published, where the use of drug-loaded micro-
particles in the management of endodontic and periodontal diseases was analyzed. Several
