Nanobiotechnology medical applications: Overcoming challenges through innovation

Nanotechnology (NT) is a dynamic revolutionary force that is exponentially impacting societies and environments globally. Through ground-breaking scientific and technological advancements, NT-based products have become integrated into the daily lives of nearly every human on the planet. The NT revolution truly embodies the interdisciplinary approach and is bringing scientists together from nearly every area of the scientific study. This world-wide collaboration is significantly enhancing the quality of construction materials, machinery, automobiles, electronics, renewable energy, transportation, common appliances, consumer products, entertainment, agriculture, microscopy, scientific instrumentation, health care, diagnostic assays, and medicinal drug discovery (1, 2, 3, 4, 5) (Fig. 1). NTs exemplify unique physiochemical properties that present novel functionality based upon their extremely small size, large surface area, and quantum-mechanical dictation (1, 3, 4-5). Although the benefits are clear, there are growing concerns about the short and long-term impact of the rapid NT expansion on the health and safety of humans and the protection of the environment (1, 3, 4). To address these concerns, the NT community is working to generate regulations for nanofabrication, nano-synthesis and waste removal

Figure 1

for the available nanoparticles (NPs) and nanomaterials (NMs) (2, 3). These additions to the NT revolution will aid in the development of products with the following properties: non-toxic, biodegradable, biocompatible, scalable, smart or programmable, eco-friendly, low energy consuming, and highly efficient (4, 5). Therefore, the future of NT has the potential to generate outstanding medical care, extremely powerful computational power, stronger and more durable machinery, eco-friendly cities, and an increase in the access to clean water and food (3, 4)(6, 7, 8).

One of the most prominent subclasses of NT is Biomedical NT (BNT), which focuses on the development of nano-based therapeutics, therapies, and diagnostic techniques that will advance health care. Currently, only a few nanomedicines out of the thousands in research and development (R&D) are FDA approved, but many BNT-based applications are being applied to the laboratory setting, such as diagnostic assays, imaging technologies, biosensors, and in vitro tissue generation (9). These innovations are enhancing the accuracy and precision of scientific research by lowering the detection limits, enabling high-throughput screening (HTS) capabilities, developing bio-mimetic in vitro and in vivo models, and allowing researchers to visualize and track their nano-products within living organisms and environmental landscapes. Through the application of these models, lead selection and optimization during the R&D of nanomedicine will be greatly enhanced, which will increase the therapeutic efficiency of the final product. Overall, the current applications of BNT are significantly enhancing scientific research, which is giving rise to precision and personalized nano-based therapies and health care.

Personalized therapies are appearing to be the next major trend in the BNT field, and will primarily focus on selecting the dose type, level and strength based upon a patient’s specific disease profile. This advancement will heavily depend on the simultaneous generation of comprehensive genomic, proteomic, metabolomics, and cytomic databases that can be used to analyze results and select the proper protocols for therapies. These omic-based studies will facilitate accurate disease diagnosis and therapy selection that will prove to be vital to the advancement of curative personalized medicine therapies for extremely high-mortality rate diseases, such as cardiovascular and neurodegenerative diseases. Another example can be seen in the development of personalized cancer therapies that will be dictated by the cross-referencing of acquired patient data with cancer-omic databases that contain information regarding the molecular or genetic carcinogenic agents, cell morphology, surface and genomic biomarkers, protein expression, symptoms, and alterations to metabolic pathways (10, 11, 12). By tailoring the design of nanoformulations to the omic-based information, they can be created to express prolonged half-life, controlled drug release, targeted delivery, stimuli-responsive behavior, and enhanced permeability across physiological barriers. Nanomedicine has quickly surpassed the capabilities of conventional pharmaceuticals. In the past, the majority of therapies were able to efficiently manage diseases, but typically did not offer the curative options that are now becoming a possibility through the BNT advancement.

Nanomedicines are designed to avoid inducing complications that a patient would typically experience with conventional pharmaceuticals, for example, toxicity induced from the administration of large, non-targeted dosages. However, nano-medicines can typically be administered at much smaller doses due to their innately high reactivity and functionalized drug delivery. Nanomedicines are often loaded within or adhered to functionalized NCs that confer enhanced therapeutic efficiency. The functionalization of NCs incorporates bioactive molecules that facilitate control over the targeted delivery and release of the payload, the selective and efficient permeation across targeted physiological barriers, and the safe excretion and degradation within living organisms (13, 14, 15, 16). These nanomedicines are beginning to be generated to treat a wide variety of health issues, including high mortality rate diseases like cancer, cardiovascular disease, and neurodegenerative disease (Table 1). Some examples of highly effective nano-therapies currently in R&D or clinical trials include tumor ablation through hyperthermia, phototherapy, or photo-chemotherapy; cardiovascular therapies utilizing targeting nanomedicines directed to sites of thrombosis and atherosclerotic plaques; and neurodegenerative therapies utilizing nanomedicines that can permeate the blood-brain barrier (BBB) in order to inhibit the progression, prevent the genesis, or possibly revert the symptoms of Parkinson’s and Alzheimer’s disease. As these BNT-enabled innovations continue to develop, many classically chronic diseases will begin to become curable.

Figure 2

Recently, many NCs are being functionalized with extracellular or intracellular stimuli-responsive behaviors that are stimulated upon interaction with a selected biomolecule or cellular environment that causes a structural or conformational change in the NC, thus inducing payload release or bioactivity (17, 18). Common stimuli found in the cellular microenvironment of most disease sites includes detectable alterations from endogenous pH, temperature, and glutathione levels (19). Extracellular stimuli can also be applied, which include induced alternating magnetic fields, photothermal energy (NIR laser), and photoacoustic waves (20). Induced changes in the NC can range from alterations in porosity to the cleavage of molecular linkers to activate a specific functionality. Techniques like these have been shown to significantly enhance the therapeutic efficiency of in vivo administration by avoiding potentially toxic non-specific interactions or premature drug release, while also ensuring that an adequate concentration of drug is delivered to the target site (18, 20, 21, 22-23).

Novel NCs are constantly in demand, and through vigorous BNT research, many have been discovered and are currently under investigation for their potential to enhance the delivery of conventional payloads or novel nanomedicines. A very common form of NCs are those made of natural polymers, which includes proteins and lipids. Polymeric NCs are biocompatible, biodegradable, and non-toxic which makes them ideal for medical application. Additionally, they can be highly function-alized in a manner that facilitates novel functionalities, and control over the therapeutic delivery and release profiles. A novel example can be seen in a recently developed star-shaped poly (l-lysine) polypeptide (star-PLL) NC that has been shown to facilitate enhanced gene therapy via highly efficient intra-cellular plasmid delivery to mesenchymal stem cells (MSCs). This delivery mechanism significantly enhanced the transgene expression of bone morphogenetic protein-2 and vascular endothelial growth factor to stimulate MSC-mediated tissue regeneration (24). The star-PLLs are cationically charged, which facilitates a simple self-assembly synthesis procedure that facilitates strong adhesion of plasmid DNA (24). This NC also presents ideal properties to act as a framework for the gene therapy of various target cells in future applications. Another example of a self-assembled polymeric NC can be seen in a Diosgenin pro-drug anti-thrombosis agent where one molecule of the pro-drug is bound to a single PEG chain via a cleavable Schiff bass bond (25). When these monomeric units are placed in solution they self-assemble into PEG micelles that confer enhanced circulation time and controlled release of the pro-drug in response to the acidic pH encountered upon arrival to the thrombus site (25). This prodrug facilitates the prevention of arterial and venous thrombus formation by increasing the subsequent Diosgenin therapies bioavailability and attraction to the desired endogenous targets (25).

Another vital group of polymeric NCs are those that are functionalized or composed of the naturally-derived polysaccharide, chitosan. Chitosan possess many ideal properties that make it therapeutically beneficial; it is biocompatible, biodegradable, mucoadhesive, antimicrobial, non-immunogenic, neuroprotective, and non-toxic (26, 27, 28). Additionally, the cationic surface charge of chitosan has been exploited in developing gene therapies to generate strong electrostatic interactions with gene silencing plasmids that facilitate stable delivery to the target site (27). Pure chitosan NPs express poor transfection rates, but modifications, such as complexation with polymers or lipids, have been shown to increase this ability (27, 28). For example, a genetically-targeted microbicide has been developed that is composed of lipids coated with a layer of chitosan that contains anti-HIV/SHIV siRNA-encoding plasmids (26). Based on the advantageous properties of chitosan, this NP was able to perform anti-HIV gene delivery to the intravaginal mucosal membrane (26). Chitosan has also been thiolated to further enhance the gene and drug delivering capabilities of the NPs. Thiol groups decrease the cationic surface charge of chitosan but does not interfere with the complexation of nucleic acids (28). In fact, this decrease in charge facilitates enhanced mucoadhesiveness, sustained drug delivery, and improved epithelial permeability (27, 28). In one study, a thiolated chitosan NC was utilized and shown to significantly enhance the anti-inflammatory effects of the anti-asthma drug, theophylline, due to the increased and prolonged absorption into bronchial epithelial cells (27). This NC presents an optimal vehicle for the treatment of cases of chronic allergic inflammation (27).

Another prominent group of polymeric NCs are lipid micelles, which have been being utilized to safely deliver toxic anti-cancer drugs to tumors. One example can be seen in the encapsulation and delivery of paclitaxel via micelles composed of a chitosan derivative, N-succinyl-chitosan, and lipoic acid (29), In addition, these micelles were bound with low-density lipoprotein complexed with siRNA targeting multi-drug resistant pathways in cancer cells (29). This NC presents acidic -stimuli responsive behavior that induces drug release at the tumor microenvironment (29). Based on the enhanced tumor cell cytotoxicity, this NC presents a promising model for the co-delivery of siRNA and anti-tumor drugs to eliminate multi-drug resistant cancer cells (29). Another example can be seen in the treatment of lung cancer via DOX encapsulated in lipid micelles (30). However, this NC is subsequently loaded within Sertoli cells, which are biocompatible, naturally-derived cells that facilitate immunoprotection during drug delivery (30). Sertoli cells also avoid the physiological rejection of encapsulated NCs, and naturally translocate, become entrapped, and lyse within precapillary vascular beds within the lung (30). The Lysis facilitates the release of the lipid micelles and has been shown to increase the anti-tumor effects of DOX due to the enhanced and stable delivery (30).

Liposomal NCs are among the few that have been FDA approved for clinical application based upon their glorified amphiphilicity that facilitates non-toxic delivery of nearly any anti-cancer drug, and for their biocompatibility that allows them to be safely excreted and degraded within the body. Recently, a novel type of PEGylated liposomes was developed, called immunoliposomes (ILs), that are revolutionizing cancer immunotherapies. ILs can safely establish anti-cancer immunity by delivering cytokines and immune agonist antibodies that often cause severe toxicity due to high systemic exposure (31). In response, PEGylated immunoliposomes (ILs) are being developed that can establish anti-cancer immunity in a non-toxic manner. In one study, ILs had the immune agonists IL-2 and anti-CD137 covalently adhered to their surface and were functionalized to express significantly enhanced permeability and retention (EPR) in order to permeate into the tumor microenvironment (31). The ILs alter the cytokines’ pharmacokinetics and biodistribution in a manner that successfully confers cancer immunity without generating toxic-effects (31).

However, a major challenge to conventional systemic drug delivery is the non-specific uptake of nanomedicines by the reticuloendothelial system (RES), which inhibits payload delivery and imparts toxicity within RES-associated organs, such as the liver, spleen, and kidney (32). In response, there has been a focus on developing nanoprimers that can prepare a patient’s body for the subsequent administration of nanomedicines in a manner that will reduce the therapy’s risk profile (33). In a recent study, it was demonstrated that the intravenous administration of intralipids one hour prior to therapy was shown to decrease RES uptake, while increasing the nano-medicine’s bioavailability (32). Intralipids interact with the RES, which allows an increased amount of the nanomedicine to arrive at the target site (32). This study found these synergistic effects to exist for anti-cancer therapies using Abraxane, Marqibo, Onivyde, and a novel platinum-containing anti-cancer nanodrug. Advantageously, it is not required that modifications be applied to the payload or its carrier in order to confer this synergism, which makes it translatable to other BNT-based therapies (32). Another similar study utilized a non-toxic liposomal nanoprimer that presented low levels of hepatic accumulation and increased the subsequently administered nanomedicine’s systemic bioavailability (33). It was found that by loading cytochrome inhibitor within the nanoprimer, the efficiency of docetaxel treatment significantly increased (33). In both cases, these lipid-based nanoprimers can be modified, through unique functional design, to express efficient priming for a broad range of nano-based therapies (32, 33).

Another novel liposomal application has been developed that utilizes liposome-nanobubble ultrasonic-responsive NCs for the enhancement of anti-cancer drug delivery (34). The LNs are comprised of phosphatidylserine and a paclitaxel payload, which confers pro-apoptotic effects that advance cancer cell death (34). In addition, the use of ultrasonic frequencies allows contrast-enhanced imaging of the location and tracking of the LNs in vivo (34). This allows them to be directly targeted with 12 MHz frequency standard B-mode sonography to induce cavitation in the structure and enhance tumor-permeability of the LN (34). This ultrasonic-induced conformational change stimulates the on-demand release of paclitaxel, and through repeated exposure to the stimulus it was found that a controlled pulsated release was able to be accomplished. The conformation change also enhances the cellular internalization of the LN 10-fold, and the expression of paclitaxel-induced anti-cancer efficacy in vitro and in vivo (34).

Novel NCs are constantly in demand, and through vigorous BNT research, many have been discovered and are currently under investigation for their potential to enhance the delivery of conventional payloads or novel nanomedicines. A very promising recently discovered group of NCs are exosomes, which are endogenous cell-derived phospholipid vesicles ranging from 30-150nm in size that express biocompatible surface chemistry to their originator cells (35). Due to their biomimetic membranes, they are being examined for their function as enhanced targeted NCs that can deliver drugs across biological membranes and are non-immunogenic due to their biocompatibility with cell membranes. Exosomes have high loading capacities and can be greatly modified through surface conjugates to derive unique functionality, such as site-directed payload delivery and release (35). Another interesting function of exosomes can be seen in their utilization in the development of proteomic libraries by comprehensively analyzing the composition of exosomes that have budded from cancer cells (36, 37). Exosomes express the same surface biomarkers and internal molecular counterparts that are expressed on their originator cell, which provides information regarding the intracellular communication and signaling between cancer cells and potential therapeutic targets that can be utilized to enhance cancer therapy (36, 37). This technique has successfully identified over 6,000 cancer-associated proteins, many bioactive-cancerous agents, and various biomarkers that can be integrated into anti-cancer therapeutics (36).

Currently, techniques are being researched that can stimulate exosome biogenesis in a manner that produces consistently sized exosomes that can be utilized for reproducible and precise drug development (35). Endogenously, the biogenesis of exosomes is involved in cellular communication and chemical signaling (35, 38). The creation of reference databases that focus on the contents, functions, locations, and stimulants of these exosomes has stimulated research focused on enhancing the rate of biogenesis and increasing their bioavailability within diseased regions. For example, the stimulation of plasma-based exosomes was induced to deliver miR-24 intracellularly, which stimulates remote ischemic preconditioning that has the potential to attenuate reperfusion and myocardial ischemia-based injuries that could lead to stroke (38). miR-24 is endogenously produced and utilized in natural exosome communication and was found to be at highest concentration within plasma-based exosomes in rats (38). Induction of these exosomes enhances the delivery of miR-24, which reduces oxidative stress and cardiomyocyte apoptotic levels by downregulating the pro-apoptotic protein Bim (38). Unfortunately, the true mechanism of the induction of these exosomes is not well-established, but through this study important anti-ischemic molecular targets and endogenous anti-ischemic agents have been identified (38). As the exosomal induction mechanism becomes known, it will be able to be exploited, either genetically or though molecular induction, so that miR-24 can be more efficiently utilized for cardiovascular therapy (38).

Nano-theranostics are nanoformulations that simultaneously deliver a payload and an imaging agent, such as a contrast agent or luminescent molecular tag, to a targeted location in order to confer therapeutic benefit, track bioactivity during administration, decrease toxicity of conventional imaging agents, and enhance the capabilities of nano-imaging instruments. By incorporating targeting moieties onto a theranostic nanoformulation, site directed imaging can be significantly enhanced, which aids in disease detection capabilities. For example, a theranostic nanoformulation is being developed that can target pancreatic cancer cells for the delivery of gemcitabine, an anticancer drug, and for labeling with gadolimium, a potent MRI contrast agent (52, 53). The major advantage is that both of these compounds are toxic in their free form and can cause many complications, but in this case, toxicity is eliminated (52, 53). The gadolinimum allows MRI tracking of the nanoformulation during systemic circulation, ensuring delivery to the target location is successful (52, 53).

However, manganese (Mn) has recently been replacing gadolinium as a less-toxic T1 MRI contrast agent. Mn also expresses paramagnetic properties and an extended plasma half-life that greatly enhance the targeting capabilities for theranostic delivery (54). For example, a PEGylated lipid micelle, DOPE, DC-Cholesterol, with a Mn-oxide core was developed for the co-delivery of siRNA-encoding plasmid DNA and DOX for the treatment of lung cancer (54). The formulation was administered intranasally to mice and was found to provide an efficient vehicle for cancer lung theranostics based upon the significant anti-cancer effect, excellent T1 MRI contrast, and enhanced accumulation within the lungs (54).

Another theranostic approach currently being developed targets the endothelial cells of inflammatory sites using novel bio-mimetic NCs called leukosomes (55). Leukosomes have properties similar to liposomes regarding their loading capacities, ability to be functionalized, and biocompatible composition due to their endogenous nature (55). In this study, the leukosomes were targeted to endothelial biomarkers, VCAM-1 and ICAM-1 (55). These markers also show promise as potential targets for early diagnosis of atherosclerotic conditions (55). The leukosomes proved to be efficient vehicles for delivery of a broad range of anti-inflammatory agents, as well as the co-delivery of MRI contrast agents (55).

Chitosan has also been utilized to functionalize many NPs so that they can perform theranostic functions that focus on delivering therapeutic plasmids and magnetic resonance imaging (MRI) contrast agents that allow the researchers to treat and visualize brains of individuals suffering from traumatic brain injury or other neurodegenerative diseases. A recently developed chitosan NP has been developed that targets the brain and incorporates manganese as a T1 MRI contrast agent (56). The manganese is contained within a cross-linking agent, Mangafodipir, that forms a stable chitosan-plasmid DNA matrix (56). Upon intranasal administration, this NP was found to efficiently translocate to the brain and is hypothesized to be endosomally internalized by olfactory sensory neurons (56). The chitosan matrix then becomes degraded by the endosomal environment, which releases the plasmids intracellularly so that they can perform gene silencing (56). Another MRI contrast agent that has been complexed with chitosan is superparamagnetic iron oxide nanoparticles (SPIONs), which also facilitate magnetofection. Magnetofection is the capability to attract NPs to a specific area of the body through the application of an external magnetic field (57). An example is SPION-containing block-polymer micelles coated with cationic polyethyleneimine (PEI) and chitosan complexed with DNA (57, 58). These micelles were able to magnetically translocate to the brain, efficiently release the plasmid DNA, and facilitate enhanced in vivo imaging (57, 58).

Additionally, chitosan has been complexed with graphene oxide to generate optimal non-toxic theranostic gene delivery vehicles that are showing promise for their applicability towards gene, chemo- and phototherapies focused on the treatment of cancer (59). The major advantage of these chitosan-graphene oxide NPs is that they can facilitate the co-delivery of anti-cancer plasmid DNA, DOX, and MRI contrast agents (59). This combinatory approach has generated a non-toxic and non-invasive platform for cancer therapy and in vivo tumor imaging and diagnostics (59).

AuNPs have also been utilized for theranostic therapies targeted to inflammatory sites that correspond to atherosclerosis (60). AuNPs of various sizes and shapes are being utilized for their ability to passively and actively target inflammatory sites based upon affinity to specific inflammatory biomarkers, such as accumulation of monocytes and macrophages in high risk plaques (60). Upon arrival, the AuNPs act as a contrast agent because they can become stimulated with photoacoustic (PA) waves emitted from a PA tomography laser (60). This produces detectable pressure acoustic waves that are induced by the thermoelastic expansion of the AuNPs (60). AuNPs also showed the ability to target sites of thrombosis through bio-markers such as the cell surface glycoprotein receptor Integrin αVβ3, which is expressed on activated endothelial cells and can be utilized to visualize CVD-related angiogenesis (60). In this study AuNPs were also presented for their capability, in cohort with PA stimulation, to induce the opening of the blood brain barrier in rats when exposed to focused-ultrasound (60). This ability would allow researchers to better diagnose and study the molecular environment of CVD-induced brain-related symptoms, such as ischemic strokes (60). Overall, AuNPs are showing great promise in regard to their ability to function as a contrast agent, and also present theranostic potential due to their large and flexible loading capacities that can be utilized for the delivery of a broad range of nanomedicines (60).

BNT-enabled diagnostics has incorporated mechanical and electrical NTs to create bioanalytical devices called Biological Micro-Electro-Mechanical Systems (BioMEMS). Initially BioMEMS application was primarily in vitro to characterize physiochemical properties of nanoparticles such as size, mass, and zeta potential; detection of specific biomarkers for disease diagnostics; or identification of contaminants or pathogens in biological samples such as body fluids, or water samples (79, 80). A major advantage of BioMEMS is their ability to perform HTS at an extremely fast rate for many samples (79, 80). However, the miniaturization and advancements towards micro-cantilever technology has further increased the accuracy, sensitivity and detection capabilities of BioMEMS while decreasing the cost, the amount of solvent and sample used per assay, and the speed of result acquisition (79, 80).The continued trend of miniaturization has led to the generation of cell-on-a-chip technologies that have the capability to perform analysis on the level of single cells (81). Also, organ-on-a-chip technologies have been generated that simulate 3D tissue environments that represent in vivo cell-cell interfaces and can accurately depict biochemical, genetic, and metabolic activities in real time (80, 81). These biosensor-based chip technologies have made it possible to detect diseases in their earliest stages due to their extremely small detection limits and their ability to detect the presence of disease cell-by-cell (80, 81). These technologies will revolutionize in vitro assays and allow simple, non-invasive, inexpensive devices for patient-performed in-home diagnostics. A limiting factor off the chip technologies is that they only allow extracellular and surface-cellular detection, but another biosensing technology called nanoscale endoscopes allows subcellular detection of organelles and cytoplasmic biomarkers (82). The endoscope non-invasively probes a cell and photonically stimulates fluorescently tagged organelles to detect diseased cells based on individual intracellular signals (82). This technique provides insight into intracellular disease profiles, which will significantly aid in the development of future therapies.

Recently, molecular electrodes have been developed for diagnostic purposes. A promising model for the electrochemical detection of mutated DNA sequences and single-nucleotide polymorphisms utilizes graphene electrodes that are functionalized with chitosan (83). Graphene’s physiochemical properties make it an excellent material for the generation of biosensors due to its exceptional electronic, mechanical, and thermal properties (83). The chitosan facilitates the covalent attachment and immobilization of a single stranded DNA sequence that is complementary to the target sequence (83). The electrode platform is added to the biosensing device, which is then subjected to voltammetry (83). During the assay completely, complementary DNA sequences bind the DNA of the electrodes. This determines if the target sequence is present in the biological sample (83). This rapid and inexpensive platform presents the potential to be utilized as a point-of-care diagnostic device that can detect disease-related DNA mutations in a sample taken from a patient (83). As this technology continues to progress multiplexed electrodes can be generated that will be able to characterize the genetic profile of an individual in comparison to a specific disease (83).

There are also many types of bioassays that are being developed that provide in vitro models that closely represent in vivo microenvironments and enhance the precision and accuracy of drug response profiling. For example, polymeric electrospun fiber-inspired smart scaffolds (FiSS) are being utilized during in vitro cancer studies to facilitate the formation of 3D tumoroids (84). The tumoroids are formed from extracted tumor cells of a specific cell line that were grown in mice (84). Advantageously, tumoroids exemplify reduced sensitivity towards anticancer drugs, which improves the quality of screenings for anticancer compounds in comparison to the classical models (84). Additionally, this technology can be utilized to culture tumor cells from patient biopsies to perform accurate diagnostics that can aid in the development of personalized cancer therapies (84). Another example can be seen in in vitro microfluidic blood brain barrier (BBB) models that accurately represent in vivo conditions (85). Additionally, single cell additive manufacturing is assisting in the generation of 3D bioprinted in vitro tissue and organ models that can be utilized in regenerative research (86).

Additionally, lipid technologies have begun to revolutionize high throughput in vitro assays by decreasing the size of each compartment (or well) on microarrays using evaporative edge lithography to stamp lipid bilayers in a specific orientation, producing microarrays with the potential to test 50,000 drug candidates in a single assay (87). This lipid technology was also used to develop lipid-oil droplet arrays that do not require additional solvent and can assay lipophilic drugs (87). These assays can also determine the dose-dependent bioactivity of large quantities of small molecules to determine their potential as a nanotherapeutic in nanomedicine (88, 89). This lipid technology has also been used in the development of “nanointaglio,” which detects analytes in air vapors by optically sensing topographical changes to lipid grates upon the passage and binding of vapor analytes (88, 89, 90). Overall, bioMEMS are completely revolutionizing in vitro analyte and disease diagnostics, biological sample analysis, NP characterization, and lead selection through bioactivity high throughput screenings.

Another truly innovative technology is the development of nano-based implants to repair damaged or inactive sensory organs, such as an artificial ear that can allow a deaf person to hear or an artificial nose that can grant someone the sense of smell (90, 91). These implants are essentially BioMEMS that are specifically functionalized to detect sensory stimuli and use the electronic aspects to send signals to the desired cells, typically central nervous system cells (90, 91). For example, a cochlear ear implant is being developed that utilizes nanoelectrodes to plasmonically stimulate neural and cardiac cells to confer the ability to hear for the hearing-impaired (91). Nano-implantable technologies, such as gradually dissolving hydrogels, are also in development for implantable diagnostic devices and implantable drug administration devices that can allow point-of-care, in-home treatment and controlled drug release without issues of patient non-compliance. The future goals of BNT include innovative technologies with the potential to facilitate drastic changes in what was once believed to be irreversible damage and permanent health conditions of the human body, such as amputation or inert deafness. These goals are being accomplished through the combination of functionalized BioMEMS, “smart” biomaterials, and 3D bioprinting technologies.

In conclusion, the BNT revolution is proving to be a continually growing dynamic force that is generating innovations that are altering the world’s perspective on medical care. Specifically, there will be a rise in the production and widespread utilization of highly therapeutic efficient personalized and precision nanomedicines and nanotherapies. This integration will facilitate the elimination of the fear of mortality from conventionally chronic or fatal diseases and is also projected to discover therapies that will extend the average lifespan. In cases where tumors or harmful growths develop precision and assisted surgical techniques are greatly advancing to the point where they can surgically remove single cells. Also, to repair surgical sites or any form of tissue damage, BNT is facilitating the generation of many platforms for tissue regeneration that utilize an individual’s cells, which will lead to the elimination of tissue implant rejection. In the future the treatment burden to a patient will be significantly decreased based upon the development of prolonged and stable delivery systems that will lower the number of administrative events. Additionally, many nanomedicines will be formulated into non-invasive, self-administrable, and high-patient-compliant administrative forms that will further increase the ability for the patient to perform in-home therapy. Diagnostic devices, such as BioMEMS, will also continue to become more cost-effective and easily functional so that patients can perform in-home point-of-care diagnostics, which will also aid in the earlier detection of disease. As these BioMEMS integrate with computer technology they will be able to perform real-time communications with health care facilities upon identification of disease and serious compliance or toxicity issues. BioMEMS will also present products that will be able to function as in vivo implants acting as functional or sensory organs. Regarding scientific development, microscopy and characterization instrumentation will continue to increase in functionality, precision, and accuracy which will lead to particle level detection and differentiation. Overall, if implemented in accordance with appropriate regulation and safety-monitoring, BNT has the potential to enhance the worldwide quality of life for humans across every continent.

This research was supported by VA Merit Review Awards #BX003685 and BX003413, and Research Career Scientist Awards to Dr. Shyam Mohapatra (IK6 BX003778) and Dr. Subhra Mohapatra (IK-6BX004212). Though this report is based upon work supported in part by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development, the contents of this report do not represent the views of the Department of Veterans Affairs or the United States Government. The Department of Veterans Affairs had no role in data collection and analysis, decision to publish, or preparation of the manuscript.