Table 2.

NP materials in targeted cancer therapy with potential in GI treatment

NP Type	Material	Advantages	Disadvantage	FDA approval/clinical status	Refs.
Polymer	PLGA	Enhanced drug solubility,improved accumulation at tumor site, completely biodegradable, non-toxic clearance, suitable for surface modifications, dual functionality when conjugated with chitosan or gold, use in photothermal therapy, vaccine and gene delivery, easy and proven processing	More toxicity studies and clinical evaluation needed, possible immunogenic properties	Approved for drug delivery. Clinical trial: PEG-PLGA docetaxel, paclitaxel PEG-PLGA, paclitaxel oncoGel	[174, 175]
	Chitosan	Antimicrobial properties, solubility, stability and biocompatability, coating for other NPs, cationic and mucoadhesive characteristics—ideal for oral delivery, permeation enhancement, pH responsive, excellent gene and cancer vaccine delivery vector	Low solubility in non-acidic pH, lack of comprehensive toxicity profile, deacetylation degree determines physio-chemical behaviour, crosslinking might prevent degradation	Approved as safe. Animal studies on DOX-chitosan. Clinical studies (mainly lung and breast cancer): chitosan NPs loaded with curcumin, cisplatin or ascorbate	[77, 176]
	Collagen	Conjugation with metal NPs, high biocompatibility, suitable for inhalation, controlled release	Delivery of collagenase desireable in cancer—not possible with collagen, difficult particle fabrication	Research: silver NP stabilized with collagen	[177, 178]
	Alginate	Mucoadhesive, pH sensitive, oral delivery, suitable for micelles, stabilizer for metal NPs	Unknown toxicity, need stabilizers	Preclinical studies: magnetic chitosan/alginate- curcumin NP, exemestane-ALG-NPs, paclitaxel-loaded ALG-NP	[155, 156]
	Cellulose	pH triggered release, completely biodegradable, oral administration, increase drug solubility	Difficult fabrication, aggregation due to hydrophylic nature, no release in acidic pH (GC), insufficient knowledge about interaction with cells and tissues	Approved: carboxymethyl cellulose. Clinical Trial: eethylcellulose + cetuximab	[76, 179, 180]
Metal	Se	Antioxidant, anti-inflammatory properties, anticancer activity, dual delivery of therapeutics like siRNA + cisplatin, curcumin SeNPs	Dual role in cancerogenesis and drug delivery—might also produce radicals, possible epigenetical modifications	Only in vitro cell studies	[167, 181, 182]
	Au	High surface to volume ratio, stable, ideal plasmon resonance for therapeutic applications like photothermal and photodynamic therapy, good biosafety profile, high permeability, scalable	Limitations regarding bioavailability of drugs, possible cytotoxicity depending on shape and size, changes in gene expression	Approval: DOX-AuNP, clinical trial: oxaliplatin-platinium-AuNP	[183]
	Superpara-magnetic $F{e}_3{O}_4$	Magnetic nanocomposites as contrast agents for MRI imaging, drug release control, hyperthermia agents, enhancement of radiation therapy	Possible immunotoxicity, toxicity due to formulation of hydroxyl radicals	Approval only for ferumoxytol (chronic kidney disease), to date no FDA approval for cancer imaging and treatment, late stage clinical trials for Nanotherm(R) ablation therapy (currently approved in Europe for Glioblastoma)	[33, 34, 184–186]
Inorganic	$Si{O}_2$ carriers	Large specific surface area and pore volume for drug loading, controlled release kinetics, targeted delivery via surface modifications, endocytotic behavior, good biocompatibility, suitable for oral administration and bioimaging	Insufficient information about clearance time, immunogenicity and accumulation in tissue, lack of toxicity data	Silica NP with C dots approved for stage I clinical trial, in vitro cell studies for Paclitaxel-loaded SeNPs	[36, 37]
	Carbon NPs/nanotubes graphene oxide, nanodiamonds	Resist harsh acidic environment, biocompatible, able to overcome GI barriers, thermal conductivity, scalable	Poor bioavailability and solubility, intrinsic toxicity	HeLa cell studies for Cisplatin delivery	[163, 187, 188]
Lipid	Liposome	Excellent solubility, high bioavailability and biocompatibility, biodegradable, drug protection, thermosensitive, multidrug loading	Rapid clearance without stabilizing conjugates, possible toxicity, poor knowledge about internalization processes,	Approval: nanoliposomal Irinotecan, PEG-liposomal doxorubicin. Clinical Trial: paclitaxel liposome, liposomal doxorubicin, cisplatin, oxaliplatin, aroplatin and GEM	[122, 189–191]
	PEG-lipid micelles	Improved stability and drug solubility, enhanced permeability and retention due to small size ($<100\text{nm}$), cell internalization, programmable thermo-responsiveness, increased effectiveness against resistant cancer, multidrug loading	Antibody response against PEG component, lack of consistent behaviour regarding biodistribution and absorption	Approved: the polymer PEG. Clinical trials: Paclitaxel micelles in combination with cisplatin, docetaxel-polymeric micelles and oxaliplatin, gemcitabine with micellar cisplatin (NC-6004), curcumin-loaded micelles	[93, 192–194]
Protein-Based	Pyruvate dehydrogenase E2	Biomimetic platforms for mimicking, viruses, dendritic cell activation, and cross-presentation, cancer vaccine platform	B16 melanoma murine model	Only delay in tumor development, no clinical studies	[195]
	Albumin	High solubility of chemodrugs like paclitaxel, various binding capacities, excellent safety profile, biodegradable	Approved: Nab-Paclitaxel	Oral delivery not possible due to degradation in GI system, binding of active agents could lead to protein conformational changes	[196]