1 3
Topics in Current Chemistry (2020) 378:13
in the literature [21–23]; these include the direct binding of a nucleic acid molecule to MNPs or the formation of chemical bonds that requires preliminary modification of the nanoparticles’ surface and/or DNA molecules. Thus, the design of
DNA-based magnetic nanocomposites for applications in nanomedicine is not easily
implemented and depends on the ultimate purpose for which that nanocomposite is
intended [24–27].
Over the last decades, a number of authors have pointed out that magnetofection or gene delivery is a fundamental stage in nanomedicine development [28–30].
It is well known that one of the fundamental steps of gene delivery is specificity
in DNA separation. However, such methodology is also important in many other
applications, such as magnetosensitive biosensors [31], theranostics [32], and vaccine preparation [33]. Even though the DNA isolation process itself remains a challenge in terms of optimization and solid phase support selection, the use of magnetic
separation is still advantageous compared to traditional techniques [34].
The aim of this review article is to briefly outline the main properties of MNPs
and MNPs/DNA biocomposites. Current information on synthesis methods, surface
modification, and DNA interactions are also discussed. Additionally, we consider a
systematic description of the DNA isolation process using MNPs and the functioning principles of other nucleic acid-based nanobiohybrid systems.
2 Synthesis, Properties, and Surface Functionalization Strategies
of Magnetic Nanoparticles
The term magnetic nanoparticle covers a wide spectrum of nanostructured materials
that have the advantageous property of being magnetic in nature, thereby enabling
their use for different applications. This description covers a wide range of nanoparticles, including metallic [35], bimetallic [36], and metal oxide nanoparticles [37], in
diverse architectures, such as core–shell structures [38] or Janus-type nanoparticles
[39]. Among these structures are the iron oxide systems that have been intensively
studied for biomedical and technological applications [29]. Magnetic iron oxide
nanoparticles (IONPs) have significant advantages because they are inexpensive to
produce, exhibit sufficient physical and chemical stability, and have sufficient biocompatibility [15]. These properties together with a proper magnetic response are
the factors determining the use of IONPs in targeted drug delivery, hyperthermia,
magnetic resonance imaging, detection of cancer biomarkers, clinical diagnosis,
bioremediation, and DNA isolation [40–43], among others. (Fig. 1).
Particle size control, phase purity, colloidal stability, and magnetic nature have
been the focus of attention during the development of methodologies [44–46]. These
features are fundamental to achieving an appropriate nanocolloid and therefore fulfilling the requirements for its use in practical applications. The main pathways for
the synthesis of IONPs, such as magnetite (Fe 3 O 4 ), can be classified as: (1) physical
methods, such as gas-phase deposition and electron beam lithography, which are difficult techniques in terms of controlling particle size [47]; (2) chemical preparation
methods, such as sol–gel, thermal decomposition, chemical coprecipitation, hydrothermal reactions, flow injection, electrochemical, and syntheses using nanoreactors
21
Reprinted from the journal
Topics in Current Chemistry (2020) 378:13
in the literature [21–23]; these include the direct binding of a nucleic acid molecule to MNPs or the formation of chemical bonds that requires preliminary modification of the nanoparticles’ surface and/or DNA molecules. Thus, the design of
DNA-based magnetic nanocomposites for applications in nanomedicine is not easily
implemented and depends on the ultimate purpose for which that nanocomposite is
intended [24–27].
Over the last decades, a number of authors have pointed out that magnetofection or gene delivery is a fundamental stage in nanomedicine development [28–30].
It is well known that one of the fundamental steps of gene delivery is specificity
in DNA separation. However, such methodology is also important in many other
applications, such as magnetosensitive biosensors [31], theranostics [32], and vaccine preparation [33]. Even though the DNA isolation process itself remains a challenge in terms of optimization and solid phase support selection, the use of magnetic
separation is still advantageous compared to traditional techniques [34].
The aim of this review article is to briefly outline the main properties of MNPs
and MNPs/DNA biocomposites. Current information on synthesis methods, surface
modification, and DNA interactions are also discussed. Additionally, we consider a
systematic description of the DNA isolation process using MNPs and the functioning principles of other nucleic acid-based nanobiohybrid systems.
2 Synthesis, Properties, and Surface Functionalization Strategies
of Magnetic Nanoparticles
The term magnetic nanoparticle covers a wide spectrum of nanostructured materials
that have the advantageous property of being magnetic in nature, thereby enabling
their use for different applications. This description covers a wide range of nanoparticles, including metallic [35], bimetallic [36], and metal oxide nanoparticles [37], in
diverse architectures, such as core–shell structures [38] or Janus-type nanoparticles
[39]. Among these structures are the iron oxide systems that have been intensively
studied for biomedical and technological applications [29]. Magnetic iron oxide
nanoparticles (IONPs) have significant advantages because they are inexpensive to
produce, exhibit sufficient physical and chemical stability, and have sufficient biocompatibility [15]. These properties together with a proper magnetic response are
the factors determining the use of IONPs in targeted drug delivery, hyperthermia,
magnetic resonance imaging, detection of cancer biomarkers, clinical diagnosis,
bioremediation, and DNA isolation [40–43], among others. (Fig. 1).
Particle size control, phase purity, colloidal stability, and magnetic nature have
been the focus of attention during the development of methodologies [44–46]. These
features are fundamental to achieving an appropriate nanocolloid and therefore fulfilling the requirements for its use in practical applications. The main pathways for
the synthesis of IONPs, such as magnetite (Fe 3 O 4 ), can be classified as: (1) physical
methods, such as gas-phase deposition and electron beam lithography, which are difficult techniques in terms of controlling particle size [47]; (2) chemical preparation
methods, such as sol–gel, thermal decomposition, chemical coprecipitation, hydrothermal reactions, flow injection, electrochemical, and syntheses using nanoreactors
21
Reprinted from the journal