Drug theranostics

1. LAB-ON-A-CHIP
PRESENTED BY : MOHAK GULATI
KAPIL SHARMA
M. PHARM. PHARMACEUTICS
UIPS, PANJAB UNIVERSITY
Submitted to: Prof. BHUPINDER SINGH
BHOOP
UIPS, PANJAB UNIVERSITY
CHANDIGARH-160014

2. INTRODUCTION
About 20 years ago, researchers excitedly announced the coming of so-called lab-on-chip devices that could
revolutionize medicine. At the time, people marveled at the possibilities: The devices would take the
capabilities of a large biochemistry lab and shrink them to a platform the size of a cell phone or smaller. With
help from a portable scanner or reader, the chips could instantly tell whether you had a chronic disease, all
from a tiny droplet of blood or other body fluid. It may have taken a while, but the tiny chips are finally
starting to emerge from the lab and are poised to make an impact.
A lab-on-a-chip (LOC) is a device that integrates one or several laboratory functions on a single integrated
circuit (commonly called a "chip") of only millimeters to a few square centimeters to achieve automation and
high-throughput screening.
LOCs can handle extremely small fluid volumes down to less than pico-litres. Lab-on-a-chip devices are a
subset of microelectromechanical systems (MEMS) devices and sometimes called "micro total analysis
systems" (µTAS).
LOCs may use microfluidics, the physics, manipulation and study of minute amounts of fluids.

3. These devices are usually made of plastic engineered with tiny
channels, valves, and pumps that can transport, mix, and
analyze proteins, DNA, and other chemicals in body fluids for
a desired testing outcome. The fluid droplets form tiny hair-
thin liquid streams that are moved around by air pressure,
electricity, or even sound to precisely maneuver them to their
destination, react with other chemicals, and ultimately yield
clues about the presence of chronic disease or invisible
pathogens.
The chips often require insertion into a portable reader or
scanner.

4. Microfluidics - Basic principle behind LOC
• A microfluidic chip is a pattern of microchannels, molded or engraved. This network of microchannels
incorporated into the microfluidic chip is linked to the macro-environment by several holes of different
dimensions hollowed out through the chip.
• It is through these pathways that fluids are injected into and evacuated from the microfluidic chip. Fluids are
directed, mixed, separated or manipulated to attain multiplexing automation, and high-throughput systems. The
microchannels network design must be precisely elaborated to achieve the desired features.
• To accurately manage fluids inside the microchannels, specific systems are required. These elements can either
be found embedded inside the microfluidic chip, such as Quake valves, or outside of it, like in the case of
pressure controllers
• There are several reasons to use microfluidics. First, to make use of a small size scale in the range of microns.
For every 3D shape type, e.g. a rectangular channel or chamber, the ratio of surface area to volume increases as
size decreases. This makes it favorable for microchannels to captures targets such as cells, germs or
nanoparticles.
• Alternatively, Magnetic or Electric fields are more effective at a short distance, making microfluidics ideal for
sensing or detecting.

6. HISTORY
• To advance the Apollo program, the United States invested billions of dollars to miniaturize calculators in order to
send them into space. In the early 50s, researchers adapted photographic technologies to create photolithography,
in order to fabricate micro-sized transistors, and thus micro-technologies and microfabrication were born.
• Using these fabrication techniques, the first real lab-on-a-chip was created in 1979 at Stanford University for gas
chromatography.
• However, major lab-on-a-chip research only began in the late 80s with the development of microfluidics and the
adaptation of microfabrication processes for the production of polymer chips. This adaptation of microfabrication
techniques to polymers is called soft-lithography.
• Then, in the 90s many researchers began to explore microfluidics and tried to miniaturize biochemical operations
such as PCR. Early lab-on-a-chip research also focused on cell biology. This is not surprising when considering
that the microchannels were the same scale size as cells. These advances allowed scientists to easily perform
operations at the single cell level for the first time.
• Eventually, researchers began to integrate all the required steps from sample collection to final analysis onto the
same chip, showing the real potential of lab-on-a-chip technologies.

7. Manufacturing Materials
1. PDMS – POLYDIMETHYLSILOXANE
- A transparent and flexible elastomer that is widely used because it is
very easy and cheap to fabricate PDMS labs-on-a-chip by casting.
Advantages – easy integration of quake microvalves for fast flow switch
and, permeability of air for cell culture and studies.
Limitations – 1. The material is subject to aging.
2. Because PDMS absorbs hydrophobic molecules, it is hard to integrate
electrodes into a PDMS chip.
3. PDMS is not compatible with high throughput chip fabrication process
such as hot embossing or injection molding.

8. 2. Thermo-polymers – eg. PMMA (polymethyl
methacrylate)
Advantages – Transparent and compatible with micrometer-sized
lithography.
More chemically inert than PDMS.
It is possible to integrate microelectrodes into them.
Limitation - More expensive than PDMS.
3. Glass –
Transparent, compatible with micrometer sized machining, chemically inert,
with a wide range of well-known chemical surface treatments and
reproducible electrode integration.
Limitation - Fabrication of glass labs-on-a-chip requires clean rooms and
researchers with a strong knowledge of microfabrication.

9. 4. Silicon – The first lab-on-a-chip was made of silicon.
Advantages – High precision of silicon microfabrication.
- Ability to integrate any kind of microelectrode and even electronics
on the same chip.
Limitations – expensive
- not optically transparent (except for IR)
- requires a clean room as well as a strong knowledge of
microfabrication.
5. Paper – Provide advantage of ultra low costs and is the main area
of focus for developing lab on chips.

10. FABRICATION TECHNOLOGIES
• Much of the work in the field of microfluidics was performed using soft lithography as introduced by
Whitesides in 1998.
• One of the principal difficulties of soft lithography originally was the requirement for cleanroom fabrication
which remains costly and time-consuming.
• Microfluidic engineers have developed a variety of methods for fabricating submillimeter channels aside from
soft lithography for various reasons, including decreased cost, faster turnaround time, cheaper materials and
tools, and increased functionality.
• It has been our experience that starting a project with the correct fabrication technique can significantly
accelerate a project’s timeline and improve the performance of the given device.

11. 1. LAMINATES
• These are created as a stack of independently cut layers which are bonded together to form channels and
microfluidic features. In these devices, each layer can be thought of in a two-dimensional flow geometry,
which is closed by the layers above and below them.
• The height of a channel is then defined by the thickness of the material that is used to form the layer. The
most simplistic layered device is one composed of three layers: an interface layer, a flow layer, and a bottom
layer.
• STEPS INVOLVED - The principal steps in forming a laminate device are
• (1) material selection,
• (2) cutting the desired microfluidic features in each layer, and
• (3) bonding the independent layers together to form one functioning device.
• For laminate microfluidic devices, each layer is cut individually. The cutting method has a significant impact
on the dimensions and the device functionality.

12. • Cutting is usually done with a knife plotter (i.e., xurography) or laser cutter because of the speed and
simplicity that each tool offers.
In both methods, the general process overview is the same: a device is designed using CAD software, the
device geometry is cut using the selected method, the inner portion is cleaned (“weeding”), and the layers of
the device are bonded together to form closed channels.
ADVANTAGES – 1. relatively inexpensive materials and instruments
2. simple process steps
3. rapid fabrication times
4. well-controlled layer depths

13. 2. MOLDING

14. 1. REPLICA MOLDING - The core of the technology relies on using photolithography to generate silicon and
photoresist molds over which a liquid-set polymer such as PDMS is poured and cured. The cured polymer is
peeled from the mold surface, and it contains a replica of the mold. By bonding the mold with a glass slide, a
closed channel is formed.
Limitations of general soft lithography techniques include pattern deformation of the mold and a potential for
defects in molded polymers such as those that can occur when removing the cast from the mold.
2. INJECTION MOLDING - Micro injection molding occurs in four basic steps. First, the thermoplastic is
precisely melted to a liquid state inside of a compressible chamber. Next, the two halves of the mold are
compressed, creating a mold cavity. Then, the thermoplastic is injected at a specific rate, filling the mold cavity.
Finally, the mold is cooled and the cast part is removed from the mold.
3. HOT EMBOSSING - Hot embossing is a process wherein thermoplastics, or polymers that become viscous
liquids at elevated temperatures, are precisely shaped using a mold, pressure, and heat. Common thermoplastics
used in microfluidics include polycarbonate, polymethylmethacrylate, cyclic olefin copolymer, and polyethylene
terephthalate [35]. In this process, a thermoplastic film is placed between two mold inserts. Next, the mold
chamber is evacuated, compressed, and heated, creating a cast of the mold. Finally, the mold is cooled and the
cast is removed.

15. 3. STEREOLITHOGRAPHY
• SL is a classic rapid prototyping technique
that works through an optical process that
builds layer on layer. Stereolithography is
ideal for creating very fine features in a rapid
manner.
• SL uses a vat of resin that is polymerized
using a structured light source to develop
each layer. The use of UV light is very
common in SL, though some resins can be
developed using longer wavelengths.
• SLA apparatuses use a focused light-emitting
diode (LED) laser and scanning galvano-
mirror to cure spots at the surface of the vat.

16. APPLICATIONS
A. Lab on a chip for chronic disease diagnosis -

17. 1. LOC systems for CRD diagnosis
• Nucleic acid is an important type of biomarker for CRD diagnosis, especially for pathogen induced CRD.
• Ritzi–Lehnert et al. presented an automated LoC system to detect respiratory viruses from nasopharyngeal
specimens. The developed disposable microfluidic processing cartridge includes a base chip, a lysis chamber
with a cap and four turning valves. Liquid motion was actuated by the four turning valves. Efficient mixing
was achieved by magnetic stir bars, which were integrated into the chip at the extraction, lysis, PCR and
hybridization chambers. The device extracts total nucleic acids from swab samples using magnetic silica
beads. The total PCR time is about half an hour while the conventional PCR takes at least several hours.
• Saliva is considered a diagnostic substitute of blood for protein biomarker test because it can be collected in a
noninvasive manner. Using only 10 μl of saliva, this platform can measure multiple protein biomarkers
simultaneously via fluorescence sandwich immunoassays in 70 min.
• Inflammatory protein biomarkers in the saliva samples include human vascular endothelial growth factor
(VEGF), interferon gamma-induced protein 10 (IP-10), interleukin-8 (IL-8), epidermal growth factor (EGF),
matrix metalloproteinase 9 (MMP-9), and interleukin-1 beta (IL-1β). Particularly, IP-10 showed the largest
difference, suggesting IP-10 as a potential highly specific biomarker for cystic fibrosis and asthma.

18. 2. LOC system for Diabetes diagnosis
• Many microfluidic paper-based analytical devices (µPADs) have been developed for glucose detection.
Compared with the conventional glucose test strips, µPADs introduce hydrophobic barriers in hydrophilic
paper to confine the fluid flow within a desired location, which improves the efficiency and control of the
reagents and allows measuring multiple analytes simultaneously.
• Covalent coupling of enzymes on the paper surface by chemical modification improves the color uniformity
inside the sensing area, which significantly decreases the test variation.
• Researchers also reported the integration of novel nanomaterials with µPAD to enhance the detection signal
like silica and gold nanoparticles increase the intensity of color and help ion colorimetric glucose detection.

19. 3. LOC systems for CKD
• The most common two markers for renal function assessment are the estimated GFR (eGFR) and the urine
albumin to creatinine ratio (UACR). eGFR is usually calculated based on the creatinine level in the blood.
Recently, cystatin C in the blood has been reported to be a more stable marker to estimate GFR.
• Nova StatSensor Creatinine meter is an electrochemical handheld analyzer and miniaturized, disposable
biosensor for whole blood creatinine test. It can give out the result in 30 s using 1.2 µL of whole blood with a
measurement range of 27–1056 μM.
• Compared with creatinine, cystatin C production is more stable and not dependent on muscle mass. Huynh et
al. combined threshold chemistry and microfluidics to allow digital colorimetric detection with naked eyes for
cystatin C concentration in serum up to 1.5-fold increase, which can indicate the progression from normal
kidney function to stage 3 CKD.
• Hanif et al. reported that creatinine can generate chemiluminescence when reacting with hydrogen peroxide
and the reaction is remarkably enhanced in the presence of cobalt ions. they developed a chemiluminescence
creatinine sensor which is much more sensitive than most reported methods and the test takes less than 1 min.

20. 4. Lab-on-a-Chip Devices for Point-of-Care Diagnostics
• Point-of-care (POC) diagnostic platforms are small medical devices which provide diagnostic results quickly in the
easiest way.
• Working with these devices does not need trained specialists and the tests can be done by the patient in a range of
settings including home, laboratory, hospital or clinic.
• Increasingly, the need for the fast diagnostic of acute diseases such as acute myocardial infarction and for home care
testing such as blood glucose monitoring in diabetic patients, has grown the interest to develop POC systems.
• The high surface area to volume ratio in microfluidic systems results in a significant decrease in the time of analysis
in LOC for POC testing.

21. • Ionic blood chemicals and metabolites can be used as biomarkers to determine various health conditions such as liver
disease, diabetes etc.
• Glucose monitoring systems for management of diabetes, have occupied the majority of the biosensor market.It use signal
amplification by a redox enzyme.
• Reaction between glucose oxidase in the test strip and the glucose in the blood will produce an electrical current which
determines the concentration of the glucose in the sample and provides numerical results for readout by the meter.
Blood glucose monitoring system: (a) Scheme of a commercial blood glucose test device, (b) different layers of a biosensor test
strip

22. 5. Organ-on-a-Chip
• “OOC” platforms are new generation of 3D cell culture models that better emulate the dynamic, physicochemical,
biochemical and microarchitecture properties of the microenvironment of living organs.
• These microfluidic cell culture platforms recapitulate the cellular microenvironment, tissue–tissue and cell–cell
interface interactions, spatiotemporal, biochemical gradients and biomechanical properties of a whole living
organ with the aim of mimicking the smallest functional unit of an organ.
• General process to fabricate a microfluidic OOC platform. Design, microfabrication, tissue culture and biological
assays are the main steps to develop an OOC microfluidic platform for biological or pharmaceutical tests.

24. Body-on-a-Chip
• Multi-OOC platforms or body-on-a-chip platforms refer to in vitro models which emulate
interactions between two or multiple human organs within a microfluidic system.
• These complex microfluidic platforms can be used to emulate interactions among divers
organs for drug discovery, toxicity tests etc.
• There are some biological challenges such as creating a suitable media for all cell types,
appropriate scaling of organs, immune responses in the system etc. that need to be
considered in multi-OOC platforms.
• Moreover, technical challenges including avoiding bubble formation in these complex
systems, maintaining long term sterility, optimizing the physiological parameters for
different organs etc. need to be addressed in these sophisticated microdevices.
• In an interesting study which was presented by Maschmeyer at al. Troglitazone, an
antihyperglycemic and anti-inflammatory drug which was withdrawn from the market
because of its toxicity effects on liver, has been tested on microfluidic platforms.
• The liver toxicity was observed in response to Troglitazone on two separate microfluidic co-
culture platforms (liver-intestine and liver-skin) which highlights the efficacy of in vitro multi-
OOC models in drug testing

25. Advantages of lab-on-a-chip compared to conventional technologies
• Low cost: Microtechnologies will decrease the cost of analysis much like they decreased the cost of
computed calculation. Integration will allow numerous tests to be performed on the same chip, reducing to
a negligible price the cost of each individual analysis.
• High parallelization: Thanks to its capacity for integrating microchannels, lab-on-a-chip technology will
allow tens or hundreds of analyses to be performed simultaneously on the same chip. This will
allow doctors to target specific illnesses during the time of a consultation in order to prescribe quickly and
effectively the best-suited antibiotic or antiviral.
• Ease of use and compactness: Lab-on-a-chip allows the integration of a large number of operations
within a small volume. In the end, a chip of just a few centimeters square coupled with a machine as small
as a computer will allow for analyses comparable to those conducted in full analytical laboratories.
Diagnostics using lab-on-a-chip will require a lot less handling and complex operations andin most cases,
they will be able to be performed on site by a nurse.
• Reduction of human error: Since it will strongly reduce human handling, automatic diagnoses done
using lab-on-a-chip will greatly reduce the risk of human error compared with classical analytical
processes done in laboratories.
• Faster response time and diagnosis: At the micrometric scale, diffusion of chemicals, flow switch and
diffusion of heat is faster. One can change the temperature in hundreds of ms (which enables, for example,
faster DNA amplification using PCR) or the mixing of chemicals by diffusion in seconds (to enable faster
biochemical reactions, for example).

26. • Low volume samples: Because lab-on-a-chip systems only require a small amount of blood for each
analysis, this technology will decrease the cost of analysis by reducing the use of expensive chemicals. Last
but not the least, it will allow to detect of a high number of illnesses without requiring large quantities of
blood from patients.
• Real time process control, and monitoring, increase sensitivity: Thanks to fast reactivity at the
microscale, one can control in real time the environment of a chemical reaction in the lab-on-a-chip, leading
to more controlled results.
• Expendable: Due to their low price, automation and low energy consumption, lab-on-a-chip devices will
also be able to be used in outdoor environments for air and water monitoring without the need for human
intervention.
• Share the health with everybody: Lab-on-a-chip will reduce diagnostic costs, the training of medical staff
and the cost of infrastructure. As a result, lab-on-a-chip technology will make modern medicine more
accessible to developing countries at reasonable costs.
• In one sentence: We can clearly expect lab-on-a-chip to save numerous lives.

27. Limitations of lab-on-a-chip compared to classic technologies
• Industrialization: Most lab-on-a-chip technologies are not yet ready for industrialization. Regarding its core application,
the ultra-multiplex diagnosis, at this time we are not certain which fabrication technologies will become the standard.
• Signal/noise ratio: For some applications miniaturization increases the signal/noise ratio and as a result, lab-on-a-chip
provides poorer results than conventional techniques.
• Ethics and human behavior: Without regulations, real-time processing and the widespread accessibility of labs-on-a-chip
may generate some fears of the untrained public diagnosing potential infections at home. Moreover, the DNA sequencing
potential of lab-on-a-chip may enable anyone to sequence the DNA of others using a drop of saliva.
• Lab-on-a-chip needs an external system to work: Even if lab-on-a-chip devices can be small and powerful, they require
specific machinery such as electronics or flow control systems to be able to work properly. Without a precise system to
inject, split and control the positioning of samples, labs-on-a-chip are useless. External devices increase the final size and
cost of the overall system and some, particularly flow control equipment, can often pose limitations for lab-on-a-chip
performance.

28. Current challenges & research
• Contemporary research on lab-on-a-chip technology focuses on three main aspects:
– The industrialization of lab-on-a-chip technologies to make them ready for commercialization. This includes the
adaptation of fabrication processes, the design of specific surface treatments, flow control system … etc.
– The increase in the maximum number of biological operations able to be integrated on the same chip and the increase in
parallelization to achieve the detection of hundreds of pathogens in the same microfluidic cartridge.
– Fundamental research on certain technologies with a high potential impact, such as DNA reading through nanopores,
which requires more investigation in order to be applicable.
• Much research is being conducted on increasing the ease of use of lab-on-a-chip. Some examples include enabling the
use of basic lab-on-a-chip functions using a smartphone for cholesterol testing , anemia diagnosis, cardiovascular
diseases monitoring or Elisa assays
• There is also much research being done to improve current technologies for given applications including cell separation,
DNA sequencing through nanopores, micro qPCR and micro reactors. In the case of microPCR, which is one of the most
promising technologies for future high throughput diagnostics, research focuses mainly on allowing high parallelization
by a multiplication of the PCR chamber, the use of digital microfluidics to perform PCR in micro-droplets and using the
latest advances in molecular biology to perform simultaneous PCR in the same mix. Research also strongly focuses on
enabling lower detection levels and increasing PCR efficiency while reducing false positives and negatives.
• Today some labs-on-a-chip are already commercialized for targeted applications such as glucose monitoring or specific
pathology detection. In a near future we can expect that labs-on-a-chip will widely be used in hospitals everywhere and
eventually in the practitioner’s office. Later on, we can expect that lab-on-a-chip technologies will be able to provide
real-time monitoring of health at home. This is why governments and companies are investing more and more in labs-on-
a-chip since it is now clear that these technologies will change our daily lives.

29. How lab-on-a-chip can change our vision of medicine
• In a near future, lab-on-a-chip devices, with their ability to perform complete diagnosis of a patient during the time of
a consultation, will change our way of practicing medicine.
• Diagnosis will be done by people with lower qualifications, thus enabling doctors to focus only on treatment.
• Real time diagnosis will increase the chances of survival for patients in emergency services and will allow the
appropriate treatment to be given to each patient.
• A complete diagnosis will greatly reduce antibiotic resistance, which is currently one of the biggest challenges of the
decade.
• The ability to perform diagnosis at low cost will also routinely change the way we see medicine and then enable us to
detect illnesses at an earlier stage and treat them as soon as possible.
• In developing countries, lab-on-a-chip will enable healthcare providers to open diagnostics to a wider population and
to give the appropriate treatment to people who really need it without the use of rare and costly medications.

30. Conclusions and perspectives
• Looking at recent researches and products entering the market, we now can be sure that lab-on-a-
chip will change the way we do diagnostics in a near future.
• Several labs-on-a-chip have been commercialized for some key applications such as glucose
monitoring, HIV detection or heart attack diagnostics.
• The challenge for industrial research will be to incorporate on the same lab-on-a-chip the
maximum number of individual operations in order to decrease costs and increase ergonomics as
well as the speed of diagnosis.
• At the moment, technologies are not unified and nobody can say which technologies and which
materials will be the most promising for high throughput diagnostics.
• The answers will depend on technological potentiality, but also perhaps on economic and industrial
points of view regarding a synergy with already installed systems such as silicon micromachining.

31. REFERENCES
• https://www.elveflow.com/microfluidic-reviews/general-microfluidics/introduction-to-
lab-on-a-chip-review-history-and-future
• Azizipour, N., Avazpour, R., Rosenzweig, D. H., Sawan, M., & Ajji, A. (2020). Evolution
of Biochip Technology: A Review from Lab-on-a-Chip to Organ-on-a-
Chip. Micromachines, 11(6), 599. https://doi.org/10.3390/mi11060599
• Gale, B.K.; Jafek, A.R.; Lambert, C.J.; Goenner, B.L.; Moghimifam, H.; Nze, U.C.;
Kamarapu, S.K. A Review of Current Methods in Microfluidic Device Fabrication and
Future Commercialization Prospects. Inventions 2018, 3, 60.
https://doi.org/10.3390/inventions3030060
• Wu, J., Dong, M., Rigatto, C. et al. Lab-on-chip technology for chronic disease
diagnosis. npj Digital Med 1, 7 (2018). https://doi.org/10.1038/s41746-017-0014-0