Table 1.

Biomaterials and antimicrobial agents for chronic wound care. Abbreviations: Montmorillonite—MMT, Stapylococcus aureus—S. aureus, Methicillin-resistant S. aureus—MRSA, Pseudomonas aeruginosa—P. aeruginosa, Escherichia coli—E. coli, Nanoparticles—NPs.

No.	Name	Short Description	Antimicrobial Properties	Ref.
A. Natural polymeric biomaterials
1.	Alginate (sodium alginate and calcium alginate)	natural polysaccharide linear copolymer of α-L-glucuronate and β-D-mannuronate, covalently linked in various arrangements hydrogel, film, foam and fibrous dressings	No intrinsic antimicrobial activity.	[16,39]
2.	Cellulose (bacterial cellulose and others)	natural polysaccharide linear chain of several hundred to many thousands of β (1 → 4)-linked D-glucose units hydrogel, hydrocolloid, film, foam and sponge	No intrinsic antimicrobial activity.	[15,64]
3.	Montmorillonite (MMT)	non-toxic medicinal clay phyllosilicate based on two tetrahedral sheets of silica sandwiching a central octahedral sheet of alumina spaced out interlayer spaces (galleries)	No intrinsic antimicrobial activity.	[34]
4.	Chitosan	the only natural polysaccharide that is positively charged (due to amino groups) derived from chitin through deacetylation films, fibers, sponges and hydrogels	Intrinsic antimicrobial activity: bactericidal and fungicidal.	[15,16,24]
5.	Other biopolymers: fucoidan, hyaluronic acid and collagen	non-toxic, biodegradable, biocompatible and non-immunogenic	No intrinsic antimicrobial activity. Permeable to pathogens.	[16,39]
B.	Inorganic antimicrobial nanoparticles (metal and metal oxide NPs) incorporated in biomaterials	structures with dimensions ranging from 1 to 100 nm metals and metal oxide NPs with intrinsic antimicrobial properties:	Intrinsic wide antimicrobial activity.
		silver—AgNPs copper—CuONPs zinc oxide—ZnONPs gold—AuNPs titanium dioxide—TiO2NPs silicon dioxide—SiO2NPs magnesium oxide—MgONPs
C.	Organic antimicrobial nanoparticles incorporated in biomaterials	liposomes, micelles and aptamers releasing the drug (antibiotics, antifungals and cytotoxic drugs or vaccines)	They release antimicrobial drugs.	[53,55,57]
D.	Plant-derived composites incorporated in biomaterials	non-toxic and high biocompatibility	Intrinsic antimicrobial activity.	[16,62,63]
		curcumin thyme oil cinnamon oil Manuka honey and Eucalyptus honey or other natural molecules/extracts
E. Antimicrobial biomaterials—examples of composites cited in this article
1		cellulose–chitosan hybrid nanocomposite with AgNPs and gentamicin	Antimicrobial	[30]
2		bacterial cellulose-copper—MMT composite	E. coli and S. aureus	[34]
3		chitosan—AgNPs	MRSA and P. aeruginosa	[37]
4		chitosan microspheres loaded with silver sulfadiazine encapsulated in PEGylated fibrin gels	S. aureus and P. aeruginosa	[38]
5		spherical AgNPs of 10–30 nm incorporated in bacterial cellulose nanofibers	E. coli, S. aureus and P. aeruginosa	[43]
6		chitosan composites enriched with different concentrations of ZnO	Biocidal effects on Gram-positive and Gram-negative bacteria	[46]
7		wound dressings loaded with TiO2NPs and coated with chitosan and pectin	Antimicrobial	[49]
8		curcumin—chitosan-PVA/Ag nanocomposite hydrogel	E. coli	[26]
9		chitosan/PVA/curcumin membrane with variable content of curcumin and chitosan	Pasteurella multocida, S. aureus, E. coli and Bacillus subtilis	[59]
10		curcumin encapsulated into a saline–hydrogel nanoparticle vector	MRSA	[13,59]
11		electrospun bioactive dressing of chitosan and curcumin	E. coli	[16]
12		1.2% thyme oil incorporated in chitosan	E. coli, Klebsiella pneumoniae, P. aeruginosa and S. aureus	[60]
13		cellulose fibrous membranes enriched with different concentrations of thymol	S. aureus and E. coli	[61]
14		cinnamon oil in alginate gel	E. coli and S. aureus	[62]