Recent Innovations in Biotechnology Class 12: PDF Download

This page covers recent innovations in biotechnology class 12 — the NCERT chapter that opens Unit V of the Class 12 Biotechnology book, paired with Chapter 13 (Entrepreneurship) — and the official chapter PDF is right below.

The chapter leads with John Gurdon’s frog nucleus experiment and moves through biofuels, GM crops, CRISPR-Cas9, organoids, nanotech and synthetic biology, ending with India’s place in the biotech future. Use the PDF as your source text; use this page to make sense of what the book teaches, section by section.

Download the official NCERT Class 12 Biotechnology Chapter 12 Recent Innovations in Biotechnology PDF from ncert.nic.in — the exact chapter file from the NCERT textbook portal, free and in its printed form, so you can follow the original text while you read the explanations on this page.

Chapter 12 at a Glance: What the File Contains

The table below shows how much the chapter holds — sections, figures, tables and exercises — so you know the file’s shape before you open it.

The chapter runs from Environmental Biotechnology (12.1) through Future Prospects (12.6), and closes with a summary and an exercise set.

Its opening biography page introduces Sir John Gurdon, who replaced the nucleus of a frog egg with the nucleus of an intestinal cell and grew a new frog — proof that a mature cell still carries the genetic instructions for every cell type.

That experiment underpinned cloning and earned Gurdon the 2012 Nobel Prize for Physiology or Medicine jointly with Shinya Yamanaka.

What This Chapter Covers: Six Fields, One Story

Before any detail, here is the route the chapter takes: it moves from cleaning up the environment (12.1) to improving crops (12.2), repairing the human body (12.3), working at the nanoscale (12.4), building organisms from scratch (12.5) and looking ahead (12.6). The six sections are not separate topics — each one extends an idea you met earlier.

• 12.1 Environmental Biotechnology — fuels from biology, microbial breakdown of waste, and bioremediation of heavy metals.
• 12.2 Plant Biotechnology — GM crops, disease and stress resistance, biofortification, CRISPR-Cas9.
• 12.3 Regenerative Medicine — grafts, stem cells, organoids and 3D bioprinting.
• 12.4 Nanobiotechnology — why nanoscale size changes properties, nanomaterials and their applications.
• 12.5 Synthetic Biology — building organisms from the bottom up.
• 12.6 Future Prospects — microbial factories, molecular pharming and India’s biotech roadmap.

The chapter repeatedly sends you back to earlier reading: bioremediation was covered in Chapter 11 of this book, GM crops in Chapter 4, CRISPR-Cas9 in Chapter 5 and stem cells in Chapter 9. Treat those as revision targets when a section here moves fast.

Key Concepts in Recent Innovations in Biotechnology Class 12

Environmental Biotechnology: Biofuels and Biodegradation

Environmental biotechnology applies living systems — naturally occurring or genetically engineered — to two jobs: cleaning up pollution and preventing it. The prevention half means producing fuel without burning more fossil carbon.

Biofuels are fuels made from biological products, including waste. When crops such as soybean, jatropha, pongamia, palm and algae are grown specifically for fuel, the fuel is called an agrofuel. The four classes are:

• Biodiesel — made by trans-esterification of vegetable oils, animal fats or waste cooking oil. It holds more hydrogen and oxygen and less carbon than fossil diesel, so it burns more completely and releases fewer particulate emissions. It runs in ordinary diesel engines with no modification — the detail students forget. European countries commonly use a 5 per cent blend, but pure biodiesel works too.
• Bioalcohol — ethanol produced by fermenting sugars released from starch or cellulose, then distilling and drying. In India the government permits up to 10 per cent ethanol blending in petrol, while the Bureau of Indian Standards recommends 5 per cent nationally. Blending cuts fossil fuel use and emissions, but blended petrol can make engines hard to start, cause sputtering, oxidise aluminium carburettor parts and rust steel engine components.
• Biogas — mainly methane with carbon dioxide, produced by anaerobic digestion of dung, manure, crops and organic waste in a digester. It serves waste removal, environmental management and energy production at once. India’s National Biogas and Manure Management Programme installed about 49.3 lakh household plants. As a vehicle fuel, however, biogas corrodes engine metal, which makes maintenance costly.
• Biomass — solid fuels such as wood, sawdust, dung cakes and agricultural waste. It is the cheapest option for poorer households, but burning it releases particulates and polycyclic aromatic hydrocarbons (PAHs) that are harmful to health.

Algae — microscopic microalgae and the large seaweeds called macroalgae — are explored as a fuel source because they grow easily, renew every year, are non-edible and yield both bioalcohol and biodiesel. The honest catch: algal biofuel is still not cost-effective.

Biodegradation is the microbial breakdown of waste, and it now reaches materials once thought permanent. Scientists have discovered bacteria that can eat plastics and are improving them to work faster.

In the same spirit, bioplastics replace petroleum-based polymers: the biodegradable plastic PHB is produced commercially by fermentation with the bacterium Alcaligenes eutropus, and engineered Arabidopsis plants can make PHB globules in their chloroplasts. PHB still costs more than synthetic polymers, and that price gap is its main limitation.

Biotechnology also touches two heavy industries. Biopulping treats wood chips with lignin-degrading fungi so pulping needs less energy and fewer chemicals, and biobleaching uses the enzyme xylanase to reduce chlorine. In oil fields, Enhanced Oil Recovery is the third stage of extraction, after primary and secondary phases; microbes and their metabolic products improve how much residual oil comes out.

Oil-eating bacteria are also the cleanup crew for spills — a genetically engineered Pseudomonas “superbug” can eat oil spills, and its construction is described in Chapter 11.

Bioremediation uses microorganisms to reduce the toxicity of pollutants such as the heavy metals arsenic, chromium, mercury, cadmium and zinc in soil or water. Choosing a strategy comes down to three principles: treatability (the pollutant can be biologically transformed into less toxic products), bioavailability (microbes can actually reach the contaminant) and bio-activity efficiency.

Plant Biotechnology: GM Crops and CRISPR-Cas9

Plant biotechnology turns genetic modification into named products — crops that resist herbicides, diseases, insects and drought, or carry extra nutrition. The chapter assumes you met GM crops in Chapter 4, so this section concentrates on what is new.

Two generations of GM crops. The first generation was built to control weeds and pests. The second generation adds tolerance to abiotic stress (drought, salt, temperature), better nutrition, and the power to move genes between unrelated organisms — bacteria, fungi, other plants and viruses. About 29 countries have adopted GM crops, with soybean, maize, cotton and canola as the major ones.

Herbicide tolerance. Herbicides such as glyphosate kill weeds but also damage the crop because they are non-selective. The common fix: engineer the crop to overproduce the enzyme the herbicide attacks, usually in the chloroplast, so the crop becomes insensitive while weeds still die.

The modified gene comes from Agrobacterium, and the commercial result is the Roundup Ready line — glyphosate-tolerant canola, soybean, corn and cotton.

Disease resistance, by pathogen type:

• Viruses — the plant receives a viral coat-protein gene. The protein acts like a vaccine and makes the plant resistant without introducing the actual virus. Named cases: papaya ringspot virus, squash yellow crookneck disease, potato mosaic and leaf roll viruses, barley yellow dwarf in wheat.
• Fungi — defensins are antimicrobial proteins found across insects, mammals, crustaceans, fish and plants. The first transgenic application was alfalfa defensin in potato against Verticillium; since then resveratrol from white grapevine protects wheat and barley from Botrytis, and the Rpi-vnt1.1 gene from Solanum venturii shields potato from late blight.
• Bacteria — lysozyme genes give potato resistance to soft rot and blackleg caused by Erwinia; genes from Erwinia and Pseudomonas syringae protect rice from wildfire disease.
• Insects — Bt (Cry) proteins from Bacillus thuringiensis bind receptors in the insect gut and destroy the gut cells. Bt cotton is the only transgenic plant India’s government has permitted for commercial cultivation, since 2002. Bangladesh became the first country in the world to approve Bt brinjal commercially, starting in 2014. Gene pyramiding stacks two or more genes in one crop; one maize hybrid stacks insect resistance with the cspB drought-tolerance trait.
• Nematodes — genetic markers plus conventional breeding produced a resistant soybean without transgenesis. The GM maize CIEA-9 from Mexico silences trehalase by antisense RNA, so the plant needs about 20 per cent less water and withstands higher temperatures.

The chapter’s boxed list of GM plants records one measurable gain per crop:

Biofortified GM crops add nutrition instead of protection:

CRISPR-Cas9. This genome editing system — a guide RNA that finds the target DNA and the Cas9 enzyme that cuts it — was covered in Chapter 5. Scientists at the University of California San Diego developed the first CRISPR-edited plants aimed at drought and disease resistance.

The break from tradition: an offspring normally inherits genetic material equally from both parents, but CRISPR can transfer a specific trait from a single parent to successive generations. It is faster, simpler and more precise than older methods and can target several genes at once; the concerns are off-target effects, occasional low efficiency and unresolved regulatory questions.

Regenerative Medicine: Grafts, Stem Cells and Organoids

Regenerative medicine replaces cells and organs lost to degeneration, trauma or disease — and, where possible, protects vulnerable cells from dying. Its oldest strategy is transplantation.

The three graft types follow the meanings of their prefixes — auto = self, allo = other, xeno = foreign:

• Autograft — transplant between sites within the same individual, e.g., a skin graft.
• Allograft — transplant from a donor to a non-genetically identical member of the same species; the most common practice, covering kidney, liver, heart, lung and pancreas transplants.
• Xenograft — transplant between two species; pig heart valves used to repair or replace a defective human heart valve.

Why stem cells. Most organ cells (liver, kidney, pancreas) are differentiated and have limited regeneration capacity, so a badly damaged organ cannot repair itself. Stem cells can both proliferate and differentiate, which makes them the tool of regenerative medicine; the stem cell types are set out in Chapter 9.

Organoids are ultra-small, self-assembled three-dimensional tissue cultures derived from stem cells — pluripotent stem cells (PSCs) or adult stem cells (ASCs). Placed in a hydrogel such as Matrigel with the right external factors, stem cells organise into clusters that mimic real tissue: spatial arrangement of mixed cell types, cell-cell and cell-matrix interactions.

Applications include organ development, disease modelling, drug penetration into a tumour’s centre, drug screening and toxicity testing. Shape even steers fate — round mesenchymal stem cells tend toward fat (adipogenic) cells, while widely spread cells favour bone (osteoblastic) differentiation.

Spheroids vs organoids. Spheroids are simpler clumps obtained by mechanically dissociating or cutting tumour tissue. The distinction the exercises test: organoids show ordered self-assembly and depend on a matrix; spheroids do not.

2D vs 3D culture. Cells in a flat monolayer all have equal access to nutrients, but inside real tissue a cell’s position decides what it receives.

That is the argument for 3D culture systems, which predict drug responses more realistically — at a price: 3D cultures are more expensive and time-consuming, have few automated and reproducible protocols, and demand careful planning and expert handling. That sentence is the answer to exercise Q4.

Bioprinting. The chapter’s bioprinting box describes therapies already in practice. The usual pipeline: image the damaged organ with a CT or MRI scan, feed the dimensions into a computer-assisted 3D bioprinter, and build a scaffold from biopolymer embedded with cells and growth-factor nanoparticles.

Named products: Carticel (a patient’s own cartilage cells expanded in culture and re-implanted), laViv (the patient’s own fibroblasts injected for cosmetic work), Dermagraft (an allogenic fibroblast patch for diabetic ulcers) and autologous platelet for wound healing.

Nanobiotechnology: Why Size Changes Everything

When a material is cut small enough, its properties stop being those of the bulk material — and that size-driven change is the whole subject of this section.

The scale. Nanoscience studies materials smaller than one micron, in the range \(10^{-9}\) to \(10^{-12}\) m. Technology that works at this scale is nanotechnology; nanobiotechnology is its application in biology and biotechnology; nanomedicine is its use in medicine for diagnosis and therapy.

The gold example. Bulk gold is the golden noble metal of jewellery. As nanoparticles, its colour depends on size: below 30 nm it is ruby red, up to 100 nm pink, and larger particles appear darker.

The reason is surface: 1 mg of gold split into spheres of 500, 100 and 10 nm multiplies the number of particles and the total surface area enormously, which raises surface reactivity.

Carbon and quantum dots. Carbon is one element, but at the nanoscale it takes distinct shapes: fullerene \(C_{60}\), single-wall and multiwall carbon tubes, and graphene. Cadmium-selenium nanocrystals, called quantum dots, fluoresce different colours depending on size, and the fluorescence does not quench under light — so they are used in fluorescence-based diagnostic tests.

Applications, one line each:

• Medicine — drug-loaded nanoparticles target the diseased site, raising bioavailability and lowering systemic toxicity. Liposomal amphotericin B shows less toxicity and higher efficacy than the free drug; paclitaxel-albumin nanoparticles and liposomal doxorubicin are used in cancer therapy; silver nanoparticles appear in wound dressings.
• Cosmetics — zinc oxide and titanium oxide nanoparticles block ultraviolet light in sunscreens; liposomal preparations and nanoemulsions carry essential oils and vitamins into skin.
• Agriculture and food packaging — precision farming improves nutrient uptake, nano-pesticides control disease with less chemical, and nanomaterials extend food preservation.
• Textiles — stain and water repellence, wrinkle-free finish, fire retardancy, electrical conductivity, and future garments that monitor health.
• Nanobiosensors and Lab on a Chip — low-cost point-of-care tests for disease biomarkers, done at the bedside with tiny sample volumes; many tests run at once using nanotechnology and microfluidics.

The chapter closes 12.4 with an honest warning: nanotechnology raises fundamental questions about new regulations, and the safety of nanoparticles in the body and environment is not fully defined. That is the basis of exercise Q7.

Synthetic Biology and Future Prospects

The last two sections step back from individual applications to a new way of doing biology itself — building organisms rather than only studying them.

Two older strategies. The reductionist approach works downward: whole organism to tissue to organelles to molecules — the territory of anatomy, histology, molecular biology and biochemistry. The integrative approach works upward, collecting data into databases and computer models; this is bioinformatics and systems biology.

Synthetic biology. In June 2004, at MIT, a third strategy was announced: build organisms from scratch, the way an engineer builds a house from bricks. This bottom-up engineering of biological components is synthetic biology, defined as a rational design approach of constructing biological components that lead to certain functions.

It needs standards and rules of composition, and it bridges biologists and engineers to reprogramme and rewire organisms.

Long DNA synthesis. The practical revolution is speed. Instead of assembling plasmids gene by gene, you edit the plasmid on a computer, save it as a text file of ATGC letters, email the sequence to a company, and receive the finished recombinant vector in about a month — where the older route took six months to a year.

The chapter notes that scientists at Johns Hopkins chemically synthesised a fully functional yeast chromosome.

What the future holds:

• Microbial factories — bacteria that synthesise chemicals and reduce the air, soil and water pollution caused by chemical plants; designed microbes that eat harmful chemicals and turn them into environment-friendly products.
• Bioremediation treatments — solid-phase, slurry-phase, in situ, and combined biological-physical-chemical treatment of contaminated soils and groundwater.
• Molecular pharming — plant-made pharmaceuticals, attractive for low-income countries that need regular supplies of medicines cheaply, with local production and needle-free delivery.
• Risks — synthetic biology could create new viruses or bioweapons, so ethical practice and strict regulation are essential.
• India — a key supplier of DPT, BCG and measles vaccines, with fast development of low-cost diagnostics; the Draft National Biotech Development Strategy 2020-24 aims to connect startups, academia and industry.

Reading the Figures: What Each Diagram Teaches

The diagrams in this chapter cluster in the medicine, nano and synthetic biology sections, and each one carries an idea the text assumes. Here is every figure, what it shows, and what to take from it.

The Nanoscale Diagram: From Atom to Sand

Fig 12.3 is a ladder of real objects placed at their actual sizes. Start near the bottom: an atom at 0.1 nm, then a fullerene molecule, a DNA molecule, a protein, a virus, a bacterium, a red blood cell, pollen — up to a grain of sand at 1 mm.

Each rung is roughly ten times the one below it, which is why a nanometre is one billionth of a metre — the scale on which the whole of 12.4 operates.

Gold at Different Sizes: Ruby-Red Nano Gold

Read Fig 12.4 in two halves. Part (a) shows bulk gold as the yellow noble metal; part (b) shows the same metal as nanoparticles whose colour depends on size — ruby red below 30 nm, pink up to 100 nm, darker for larger particles.

The diagram illustrates why surface area matters: the same 1 mg of gold, split into ever smaller spheres, multiplies particle number and surface area enormously, and more surface means more reactivity.

Carbon Shapes and Quantum Dots: Same Element, Different Properties

Fig 12.5 shows one element, carbon, in four nanoscale arrangements: fullerene \(C_{60}\), a single-wall carbon tube, a multiwall carbon tube, and a flat graphene sheet. Shape, not chemistry, decides the property.

Fig 12.6 makes the same point for size: cadmium-selenium quantum dots of different sizes fluoresce different colours, and the fluorescence does not quench with light — which is why quantum dots appear in fluorescence-based diagnostic tests.

The EPR Effect: How Drug Carriers Reach Tumours

Fig 12.8 draws the two sides of a blood vessel. Healthy vessels have tight endothelial linings, so nanoparticles stay inside. Tumour vessels are leaky — their endothelial cells have gaps. Drug-loaded nanocarriers of 20 to 30 nm slip through the gaps, accumulate in the tumour and are retained there.

That is the enhanced permeability and retention (EPR) effect — the mechanism behind paclitaxel-albumin nanoparticles and liposomal doxorubicin in cancer therapy.

Nanotechnology’s Reach: One Technology, Many Sectors

Fig 12.7 is a map with nanotechnology at the centre, radiating into chemicals, textiles, consumer products, cosmetics, health, energy, agriculture, industry and the environment. It explains why the chapter calls nanotechnology an enabling technology rather than a single product — and it previews the application list: nanomedicine, sunscreens, nano-pesticides, smart textiles and biosensors.

Organoid Models and 2D versus 3D Culture

Fig 12.1 places organoids on the ladder of biological model systems, from subcellular components up to the whole body. Organoids sit at moderate complexity: more realistic than a monolayer or tissue explant, easier to probe than a whole organism, and able to mimic cell-cell and cell-matrix interactions while supporting long-term culture.

Fig 12.2 contrasts a flat 2D monolayer with a 3D culture; the point is that in real tissue a cell’s position decides its nutrient access, which a monolayer cannot reproduce. Together the two figures explain why organoids are called a bridge between existing model systems — the idea behind exercises Q4, Q5, Q8 and Q10.

Bioprinting and Synthetic Biology: Building to Order

The bioprinting diagram shows the pipeline from the chapter’s bioprinting box: a CT or MRI scan gives the organ’s exact dimensions, and a computer-assisted 3D bioprinter builds a scaffold from biopolymer embedded with cells and growth-factor nanoparticles. Fig 12.9 sums up synthetic biology as the amalgamation of associated disciplines — biology, engineering and computing — feeding biomanufacturing, diagnostics, cheaper therapeutics and green fuels.

Both figures point to the chapter’s forward-looking tone in 12.6.

Definitions to Know: The Chapter’s Vocabulary

The exercises test terminology precisely, so this table collects the terms the book itself defines. Terms marked * are asked about directly in the exercise set.

Common Mistakes in This Chapter

Several exercise questions exist precisely because students mix up these pairs. The table names each confusion before the test, with the correction from the chapter.

The chapter adds two cautions of its own: algal biofuel is promising but not yet cost-effective, and the bioplastic PHB is still costlier than synthetic polymers.

How the Chapter’s Exercises Test You

The chapter ends with an exercise set that tests definitions, differences and named examples — exactly the recall this page has been building. Use the map below to revise in the book’s own order.

The two assertion-reason items show a board-style format inside the textbook: judge the statement and the explanation separately, then ask whether the explanation actually accounts for the statement.

Several answers demand a named example — Roundup Ready for herbicide tolerance, Carticel and Dermagraft for cell therapy, liposomal doxorubicin for the EPR effect, fullerene for carbon nanomaterials. Memorising the chapter’s examples is its real demand.

One honest caveat: textbook contents and the examinable syllabus are not always identical — check the current official CBSE syllabus before assuming every section is examinable.

Quick Chapter Recap: Points NCERT Repeats

The chapter closes with a summary it expects you to remember. Here it is, compressed into ten points:

• Environmental biotechnology covers bioremediation and prevention — biofuels, biodegradation and biodegradable products.
• The four biofuel classes are biodiesel, bioalcohol, biogas and biomass.
• Biodegradation enables environment-friendly recycling of waste.
• Bioremediation of heavy metals (As, Cr, Hg, Cd, Zn) is done by plants and microorganisms such as bacteria and fungi.
• The two generations of GM crops deliver resistance to herbicides, biotic and abiotic stress, plus improved nutrition.
• Regenerative medicine aims to replace cells and organs lost to degeneration, trauma or disease.
• Stem cells form organoids from pluripotent and adult stem cells — 3D self-organised models for tissue and organ substitution.
• Nanoscience deals with materials smaller than one micron, in the range \(10^{-9}\) to \(10^{-12}\) m; nanomedicine and nanobiosensors are its strongest arms.
• Synthetic biology is a rational design approach of constructing biological components leading to functions.
• Automation and artificial intelligence in designing and building plasmids reduce time and cost.

The chapter opens with its promise — GM crops, diagnostics, oil-eating bacteria, lab-grown organs and biofuel that cuts the carbon footprint — and closes with India’s vaccine role (DPT, BCG, measles) and the Draft National Biotech Development Strategy 2020-24.

Related Resources: Earlier and Next Chapters

This listing is maintained for the 2026-27 academic session using the NCERT textbook information available to us. NCERT remains the authority for confirming the latest edition.

This chapter leans on the chapters before it and hands over to the one after it. Use these links to move through the book:

• Chapter 11: Bioremediation — the biodegradation detail this chapter references repeatedly.
• Chapter 13: Entrepreneurship — completes Unit V with the business side of biotechnology.
• Class 12 Biotechnology chapter list — the full set of chapters in this book.
• Class 12 study hub — all subjects in one place.
• CBSE notes home — every class and subject covered here.

Beyond Chapters 11 and 13, this chapter draws on Chapter 4 (GM crops), Chapter 5 (CRISPR-Cas9) and Chapter 9 (stem cells) without repeating their basics. The complete set of official textbooks is on the NCERT textbook portal, where the full Class 12 Biotechnology book can be opened chapter by chapter.

Sources and Data Verification

This page describes NCERT’s Class 12 Biotechnology textbook, Chapter 12 (Recent Innovations in Biotechnology), as published on ncert.nic.in — the same edition whose PDF is linked above. Every topic, figure and exercise named here comes from that textbook, and nothing has been added from other sources.

The page is maintained for the current academic session using the NCERT information available to us. NCERT settles the textbooks, their editions and the official PDFs; CBSE settles the curriculum, syllabus and examinations.

Reference: NCERT Class 12 Biotechnology textbook, chapter 12, official edition on ncert.nic.in.

FAQs on Recent Innovations in Biotechnology

What is the difference between biodegradation and bioremediation?

Biodegradation is the microbial breakdown of waste materials, including plastics that otherwise take centuries to decompose. Bioremediation uses organisms to reduce the toxicity of pollutants such as heavy metals (As, Cr, Hg, Cd, Zn) in soil or water, guided by the three principles of treatability, bioavailability and bio-activity efficiency.

Incineration, burning organic waste, is the separate non-biological option in exercise Q9.

Why does gold turn red at the nanoscale?

Bulk gold looks golden, but at the nanoscale colour depends on size: particles under 30 nm are ruby red, up to 100 nm pink, and larger particles appear darker. Splitting 1 mg of gold into smaller spheres multiplies the particle number and surface area enormously, raising surface reactivity — the property nanobiotechnology exploits.

What is the difference between an organoid and a spheroid?

Organoids are ultra-small, self-assembled three-dimensional tissue cultures derived from pluripotent or adult stem cells; they show ordered self-assembly and depend on a matrix. Spheroids are simpler aggregates obtained by mechanically dissociating or cutting tumour tissue, without that ordered assembly.

How is CRISPR-Cas9 different from earlier GM crop techniques?

CRISPR-Cas9 uses a guide RNA paired with the Cas9 enzyme to edit genes directly. It is faster, simpler and more precise than older genetic manipulation, can target multiple genes, and can transfer a specific trait from a single parent to successive generations — unlike Mendelian equal inheritance. Its concerns are off-target effects, occasional low efficiency and regulatory issues.

Which GM crops have been approved in India and what was Bangladesh’s role?

India’s government has permitted Bt cotton for commercial cultivation since 2002 — the only transgenic plant so permitted. Bangladesh became the first country in the world to approve the commercial planting of Bt brinjal, which started in 2014.

What is the EPR effect in nanomedicine?

EPR stands for enhanced permeability and retention. Tumour blood vessels are leaky, with gaps in their endothelial lining, so drug-loaded nanocarriers of 20 to 30 nm pass through the gaps, accumulate in the tumour and are retained there. Paclitaxel-albumin nanoparticles and liposomal doxorubicin are named examples used in cancer therapy.