Nanotechnology for Cancer Treatment

Background and Introduction

Cancer

Development of abnormal cells that divide uncontrollably which have the ability to infiltrate and destroy normal body tissue

Chemotherapy

Nonspecificity Toxicity Adverse side effects Poor solubility

Use of anti-cancer (cytotoxic) drugs to destroy cancer cells. Work by disrupting the growth of cancer cells

Defects

interdisciplinary research, cutting across the disciplines of

Biology Chemistry Engineering Physics Medicine

Cancer Nanotechnology

Semiconductor quantum dots (QDs) Iron oxide nanocrystals Carbon nanotubes Polymeric nanoparticles LiposomesGold NP

Structural OpticalMagnetic

Nanoparticles

Unique Properties

• Tumors generally can’t grow beyond 2 mm in size withoutbecoming angiogenic (attracting new capillaries) becausedifficulty in obtaining oxygen and nutrients.

• Tumors produce angiogenic factors to form new capillarystructures.

• Tumors also need to recruit macromolecules from the bloodstream to form a new extracellular matrix.

• Permeability-enhancing factors such as VEGF (vascularendothelial growth factor) are secreted to increase the permeability of the tumor blood vessels.

Tissue selectivity

Tissues with a leaky endothelial wall contribute to asignificant uptake of NP. In liver, spleen and bonemarrow, NP uptake is also due to the macrophagesresiding in the tissues.

• In solid tumors the uptake of NP depends on the so-called enhanced permeability and retention effect (EPR).

TUMOR-TISSUE TARGETING

Schematic of EPR (enhanced permeability and retention) effect in solid tumors:

EPR, in principle, is based on passive targeting

This passive targeting process facilitates tumor tissue binding, followed by drug release for cell killing. Nanovehicles which fail to bind to tumor cells will reside in the extracellular (interstitial) space, where they eventually become destabilized because of enzymatic and phagocytic attack. This results in extracellular drug release for eventual diffusion to nearby tumor cells and bystander cell.

How EPR works

1- nanovehicles passively target to vasculature and extravasate through fenestrated tumor vasculature.

2- the extended circulation time (stealth features) allows accumulation in tumor tissue

3- lack of lymphatic drainage prevents removal of nanoparticles after extravasation

Clinical Example of EPR

. Marketed by Ben Venue Laboratories of J&J. Approved by the FDA for treatment of ovarian cancer and multiple myeloma and an AIDS-related cancer.

Doxil is a polyethylene glycol (PEG)-coated liposomal formulation of doxorubicin

In vivo distribution of long-circulating radiolabeled liposomesi.v. injected into C26 tumour-bearing mice

DOXORUBICIN pharmacokinetics

How Doxil works?

Doxorubicin interacts with DNA byintercalation and inhibition ofmacromolecular biosynthesis.

This inhibits the progression of theenzyme topoisomerase II, which relaxessupercoils in DNA for transcription.

Doxorubicin stabilizes the topoisomeraseII complex after it has broken the DNAchain for replication, preventing the DNAdouble helix from being resealed andthereby stopping the process ofreplication.

Liposome-encapsulated doxorubicin is less cardiotoxic than freedoxorubicin.

Polyethylene glycol results in preferential concentration of Doxil inthe skin-----a side effect known as hand-foot syndrome:Small amounts of the Dox can leak from capillaries in the palms ofthe hands and soles of the feet.>50% of patients treated with Doxil developed hand-footsyndrome.

Doxil Side Effects

Example of an Approved Anticancer AgentABRAXANE : Protein-bound paclitaxel is an injectable formulation of paclitaxel,a mitotic inhibitor drug used in the treatment of breast cancer, lungcancer and pancreatic cancer.

Paclitaxel

Albumin

ABRAXANE Clinical Trial ResultsrecTLRR (PRIMARY END POINTS) VS. PACLITAXEL INJECTION FOR ALL

RANDOMIZED PATIENTS IN THE PHASE III TRIAL IN METASTATIC BREAST CANCER

SIGNIFICANTLY SUPERIOR TUMOR RESPONSE RATE IN ALL RANDOMIZED PATIENTS

EFFICACY DEMONSTRATED IN SECOND-LINE METASTATIC PATIENTS AND PATIENTS WHO RELAPSED WITHIN 6 MONTHS OF ADJUVANT CHEMOTHERAPY

Target: microtubuliAntimitotici inibizione di assemblaggio

stabilizzazione polimeri.

Microtubuli: polimeri di tubulina: crescita richiede GTP alle estremita’ e sui monomeri.Idrolisi di GTP a GDP disassembla microtubulo. Per la stabilità servono MAP

Is Abraxane Safe?

• On Jan, 25, 2014: 1,893 people reported to have side effects when taking Abraxane. Among them, 25 people (1.32%) have Renal Failure.

< 1 month

1 - 6 months

6 - 12 months

1 - 2 years

2 - 5 years

5 - 10 years

10+ years

Renal failure

83.33% 16.67% 0.00% 0.00% 0.00% 0.00% 0.00%

Time on Abraxane when people have Renal failure :

Caelyx® is a form of doxorubicin| that is enclosed in liposomes.(Janssen). It is sometimes known as pegylated doxorubicinhydrochloride (PLDH). It is used to treat:•Advanced ovarian cancer that has come back after beingtreated with a platinum-based chemotherapy drug.•Women with advanced breast cancer who have an increasedrisk of heart damage from other chemotherapy drugs.• Aids-related Kaposi’s sarcoma .

Myocet® , another form of liposomal doxorubicin, is used totreat advanced (metastatic) breast cancer| in combination withanother chemotherapy drug, cyclophosphamide| .

TUMOR-TISSUE TARGETING

Conventional Nanoparticles

• Size > 100 nm.

• Delivery to RES tissues.

• Rapid effect (0.5-3 hr).

• For RES localized tumors (hepatocarcinoma, hepatic metastasis, non-small cell lung cancer, small cell lung cancer, myeloma, lymphoma).

Long-circulating Nanoparticles

• Size < 100 nm, “Stealth”, invisible to macrophages.

• Hydrophylic surface to reduce opsonization (e.g. PEG)

• Prolonged half-life in blood compartment.

• Selective extravasation in pathologicalsite.

• For tumors located outside the RES regions.

• Gradually absorbed by lymphatic system.

Active Targeting

• On the horizon are nanoparticles that will actively target drugs to cancerous cells, based on the molecules that they express on their cell surface.

• Molecules that bind particular cellular receptors can be attached to a nanoparticle to actively target cells expressing the receptor. Active targeting can even be used to bring drugs into the cancerous cell, by inducing the cell to absorb the nanocarrier.

• Active targeting can be combined with passive targeting to further reduce the interaction of carried drugs with healthy tissue.

• Nanotechnology-enabled active and passive targeting can also increase the efficacy of a chemotherapeutic, achieving greater tumor reduction with lower doses of the drug.

http://nano.cancer.gov/learn/impact/treatment.asp

Saturation of receptors affects the specificity of targeting.

Ruoslahti E et al. J Cell Biol doi:10.1083/jcb.200910104

TUMOR-CELL TARGETING

MDR Reversion

Brigger et al., 2002

A) Free doxorubicin enters into the tumor cells by diffusion but is effluxed by Pgp, resulting in the absence of therapeutic efficacy.

B) Doxorubicin-loaded NPs adhere at the tumor cell membrane where they releasetheir drug content, resulting in microconcentration gradient ofdoxorubicin at the cell membrane, whichcould saturate Pgp and reverse MDR

V di uscita del farmaco(Attività Pgp)

[Conc. intracellulare farmaco]

V di ingresso farmaco

[farmaco esterno]-[farmaco interno]

Vascular targetsVascular endothelial GFVascular cell adhesion moleculeMatrix metalloproteinases

Tumour targetsHuman epidermal receptorTransferrin receptorFolate receptorSpecific tumour cell surface markers

Affinity-based targeting of tumors.

Ruoslahti E et al. J Cell Biol doi:10.1083/jcb.200910104

© 2010 Ruoslahti et al.

ANTICANCER DRUG

PHYSIOLOGICAL BARRIERSnon cellular based mechanisms

DRUG RESISTANCEcellular based mechanisms

DISTRIBUTION, CLEARANCE OF DRUG

•Poorly vascolarized tumorregion•Acidic enviroments intumors

•Biochemical alterations

•Large volume ofdistribution•Toxic side-effects onnormal cells

•Passive diffusion•EPR

•Endocytosis/phagocytosisby the cells•Overcome MDR

Controlled tumoral interstitial drug release

DRUG

Zhang et al., 2008

Alexis et al., 2009

Approaches In Trial or Ready Soon• Drs. Caius Radu, Owen Witte and Michael Phelps at the Nanosystems Biology Cancer

Center (Caltech/UCLA CCNE) have developed a series of positron emission tomography (PET) imaging agents. These agents are being tested for assigning patients for chemotherapy with drugs such as gemcitabine, cytarabine, fludarabine, and others used to treat cancers including metastatic breast, non-small cell lung, ovarian, and pancreatic, as well as leukemia and lymphomas. Tumors responsive to these drugs show up as bright images in PET scans when patients are first dosed with imaging agent. Biodistributionstudies have been conducted in eight healthy volunteers. Clinical development is being conducted by Sofie Biosciences.

• At the Center of Nanotechnology for Treatment, Understanding, and Monitoring of Cancer (NANO-TUMOR) (UCSD CCNE), Dr. Thomas Kipps developed a chemically engineered adenovirus nanoparticle to deliver a molecule that stimulates the immune system. Phase I clinical trials, being run jointly by Memgen and the Leukemia & Lymphoma Society, are underway in patients with chronic lymphocytic leukemia. An ongoing Phase I dose escalation study is evaluating patients who received direct intranodal injection of the chemically-engineered virus. Systemic clinical effects have been observed with a single injection with significant reductions in leukemia cell counts and reductions in the size of all lymph nodes and spleen. One patient went into complete remission.

http://nano.cancer.gov/learn/now/clinical-trials.asp

Approaches In Trial or Ready Soon

• Calando Pharmaceuticals, founded by Dr. Mark Davis at the Caltech/UCLA CCNE, is conducting clinical trials with a cyclodextrin-based nanoparticle that safely encapsulates a small-interfering RNA (siRNA) agent that shuts down a key enzyme in cancer cells. This open-label, dose-escalating trial is testing the safety of this drug in patients who have become resistant to other chemotherapies. Calando is also conducting clinical trials cyclodextrin-based polymer conjugated to camptothecin. This trial is also an open-label, dose-escalation study of IT-101 administered in patients with solid tumor malignancies.

• At the Siteman Center of Cancer Nanotechnology Excellence (Washington UniversityCCNE), Drs. Gregory Lanza and Samuel Wickline have developed a nanoparticle magnetic resonance imaging (MRI) contrast agent that binds to the αvβ3-integrin found on the surface of the newly developing blood vessels associated with early tumor development. Kereos, which was founded by Alliance investigators, is conducting Phase I clinical trials with this agent to assess its utility in the early detection of cancer.

http://nano.cancer.gov/learn/now/clinical-trials.asp

• A nanoparticle designed to cross the blood-brain barrier and specifically target glioblastomasis also nearing clinical trials. This nanoparticle agent can function as both an MRI contrast agent and a drug delivery device. Developed by Dr. Miqin Zhang - Univ. Washington Cancer Nanotechnology Platform Partnership for Pediatric Brain Cancer Imaging and Therapy.

http://nano.cancer.gov/learn/now/clinical-trials.asp

Approaches In Trial or Ready Soon

Destruction from Within

• Moving away from conventional chemotherapeutic agents that activate normal molecular mechanisms to induce cell death, researchers are exploring ways to physically destroy cancerous cells from within.

• One such technology—Gold Np—is being used in the laboratory to thermally destroy tumors from the inside. GOLD NP can be designed to absorb light of different frequencies, generating heat (hyperthermia). Once the cancer cells take up the NP scientists apply near-infrared light that is absorbed by the nanoshells, creating an intense heat inside the tumor that selec tively kills tumor cells without disturbing neighboring healthy cells.

http://nano.cancer.gov/learn/impact/treatment.asp

Thermal ablation of cancer is gaining increasing attention as an alternative to standard surgical therapies , especially for patients with contraindications.

Potential benefits of thermal ablation include reduced morbidity and mortalityin comparison with standard surgical resection and the ability to treat nonsurgical patients.

There is a wide range of ablation techniques that include : cryoablation, radiofrequency ablation, microwave ablation, ultrasound ablation and laser ablation.

Plasmonic photothermal therapy (PPTT) is a technique of cancer thermal therapy based on the laser heating of gold nanoparticles. One of the main advantages of this therapeutic technology is its high spatial selectivitythat prevents surrounding healthy tissuesfrom thermal damage.

By changing the shape of nanoparticles from spheres to nanorods, the absorption or scattering wavelength changes from the visible to the near-IR (NIR) region and offers the advantages of larger absorption and scattering cross-sections and much deeper penetration in tissues. Recent studies have shown that gold nanorods (GNRs) attached to antibodies and viralvectors could be used for selective and efficient photothermal therapy,.

The resonant wavelength is redshifted from the visible (for spherical nanoparticles, with R=1) to near-IR (for nanorods, with R > 1). R: Aspect ratio. NIR: Near-IR.

Dependence of the temperature increment ∆T on the concentration of gold nanorods in the suspension after irradiation with laser light (810 nm, 1

W/сm2 ) during 5 min.

2 D distribution of temperature over the surface of mice skin before the laser

irradiation, in 1 min and in 5 min.

before laser irradiation 1 min 5 min

Molecular Cancer Imaging (QDs)

Tumor Targeting and Imaging

size-tunable optical properties of ZnS-capped CdSe QDs

Emission wavelengths are size tunable (2 nm-7 nm) 4

High molar extinction coefficients

Conjugation with copolymer improves biocompatibility, selectivity and decrease cellular toxicity 5

Correlated Optical and X-Ray Imaging

High resolution sensitivity in detection of small tumors

x-rays provides detailed anatomical locations

Polymer-encapsulated QDs

No chemical or enzymatic degradations

QDs cleared from the body by slow filtration or excretion out of the body