Integration of biosensors and drug delivery technologies for early detection and chronic management of illness

Abstract

Recent advances in biosensor design and sensing efficacy need to be amalgamated with research in responsive drug delivery systems for building superior health or illness regimes and ensuring good patient compliance. A variety of illnesses require continuous monitoring in order to have efficient illness intervention. Physicochemical changes in the body can signify the occurrence of an illness before it manifests. Even with the usage of sensors that allow diagnosis and prognosis of the illness, medical intervention still has its downfalls. Late detection of illness can reduce the efficacy of therapeutics. Furthermore, the conventional modes of treatment can cause side-effects such as tissue damage (chemotherapy and rhabdomyolysis) and induce other forms of illness (hepatotoxicity). The use of drug delivery systems enables the lowering of side-effects with subsequent improvement in patient compliance. Chronic illnesses require continuous monitoring and medical intervention for efficient treatment to be achieved. Therefore, designing a responsive system that will reciprocate to the physicochemical changes may offer superior therapeutic activity. In this respect, integration of biosensors and drug delivery is a proficient approach and requires designing an implantable system that has a closed loop system. This offers regulation of the changes by means of releasing a therapeutic agent whenever illness biomarkers prevail. Proper selection of biomarkers is vital as this is key for diagnosis and a stimulation factor for responsive drug delivery. By detecting an illness before it manifests by means of biomarkers levels, therapeutic dosing would relate to the severity of such changes. In this review various biosensors and drug delivery systems are discussed in order to assess the challenges and future perspectives of integrating biosensors and drug delivery systems for detection and management of chronic illness.

Figure 1.

Routes of obtaining biomarkers for a variety of illnesses. 1. Spinal fluid [11]; 2. Saliva [12]; 3. Breath [13]; 4. Urine [14]; 5. Blood [15]; 6. Sweat [16]; 7.Nucleotides [17].

Figure 2.

Schematic depicting functional principles of a biosensor.

Figure 3.

A schematic depicting antibodies and antigens as immunosensor prototypes and genome probe as genosensor prototype (Adapted from [53]).

Figure 4.

Amperometric immunosensor based on a new electrochemical detection scheme (adapted from [75]).

Figure 5.

A schematic depicting the prototype label free immunosensor (adapted from [80]).

Figure 6.

Mechanism of bioreporters (adapted from [81]).

Figure 7.

A schematic depicting the basic mechanism of glucose sensor [43]. Commercial glucose biosensors: Ultimate EZ Smart Plus test strips (EZ Smart) and Contour blood glucose test strips (Bayer Healthcare LCC).

Figure 8.

A schematic showing an immobilized enzyme biosensor (adapted from [96]). Commercial cholesterol biosensors: CardioChek Cholesterol meter and Cholesterol Biometer cholesterol (Polymer Technology Systems, Inc.).

Figure 9.

Functionalized nanoparticles used in imaging biosensors (adapted from [99]).

Figure 10.

Different modes of drug delivery system synthesis. A. Nanoparticles/macroparticle/liposome formation [106]; B. Physically cross-linked hydrogels [107]; C. Chemically cross-linked hydrogels [108]; D. Polymerization/grafting/molecular imprint [109].

Figure 11.

Nanoparticles as target specific drug delivery system. 1. Blood brain barrier [137]; 2. Aerosol [138]; 3. Gene therapy [139]; 4. Mucoadhesion [140]; 5. Intracellular [141].

Figure 12.

Photolithography process (Adapted from [147]).

Figure 13.

Reversible antigen responsive hydrogel (adapted from [114]).

Figure 14.

Micro-reservoir and microvalves in microfluidics technology (adapted from [162]).

Figure 15.

Technologies for integration of biosensors and drug delivery systems.