Table A1.

An overview of the therapeutics, results and conclusions of the reviewed studies

Nanomedicine	Therapeutic	In vitro / in vivo model	Results	Conclusions	Reference
Nanofibers	RAD 16-II (amino acid sequence – Arg-Ala-Asp) peptide nanofibers mainly targets revascularisation	Both in vivo and in vitro. In vitro model: Primary microvascular endothelial cells (MVECs) isolated from mouse lung tissue. In vivo model: Diabetic induced mice were wounded – extent of healing of nanofibers was compared with that of saline and nanofibers with no affinity (KFE-8 (LysPhe-Glu)).	In vitro: formation of robust capillary like networks at 24h. In vivo: noticeable wound closure and granulation tissue formation at day 7 (p<0.01).	The low affinity of RAD to the RGD (Arg-Gly-Asp) motif of the integrin αvβ3 produced granulation tissue more quickly than a high affinity ligand (RGD), or a ligand with no affinity (KFE-8).	Cho H et al., 2012 [9]
Nanofibers	PLGA (poly (lactic-coglycolic acid)) and metformin were first dissolved in HFIP (hexafluoroisopropanol) and spun into nanofibrous membranes	In vivo model: Diabetic induced mice were given wounds 8mm in diameter. The extent of healing of PLGA/ metformin nanofibers was then compared with that of virgin PLGA and a gauze sponge.	Healing of the PLGA/ metformin nanofibers was statistically greater that the 2 control groups after 14 days (p< 0.01).	The metformin delivered by the nanofibers enabled the construction of a water-soluble matrix that was conducive to reepithelisation.	Lee CH et al., [10]
Nanofibers	EGF was ingrained (rhEGF nanofiber) and contained within (rh-EGF nanofibers) nanoscaffolds (2 separate therapies).	In vivo model: Wounded diabetic mice healing was measured for 14 days under 4 different therapies: rh-EGF nanofiber, rh-EGF nanofibers, nanofibers and a saline control.	Healing of the rhEGF nanofiber treatment was statistically greater than the other 3 groups after 7 days but not after 14 days (p<0.05)	EGF is required for the early stages of diabetic wound healing and a small dose of EGF ingrained in a nanoscaffold can improve healing.	Choi JS, et al., [11]
Nanofibers	G-CSF loaded chitosan nanoparticles incorporated in PCL (polycaprolactone) nanofibers, followed by surface coating with collagen type I.	In vivo model: Male rats were given 2 cm diameter wounds. Rats were split into 4 groups and wounds were either covered in gauze, a hydrocolloid dressing, an empty nanoscaffold or a nanoscaffold with GCSF.	The G-CSF nanoscaffold significantly reduced wound area for the first 14 days (p<0.05), with significantly more collagen and fibroblasts in the G-CSF nanoscaffold wound than the controls throughout the 21 days of the investigation.	The release of GCSF from a nanoscaffold can improve fibroblast proliferation, collagen production and reduce scarring.	Tanha S et al., 2017 [12]
Nanofibers	PLGA microspheres incorporated into PLLA (polylactic acid) nano-fibrous scaffolds.	In vitro model: The nanoscaffolds were added to plates of human fibroblasts and the rate of PDGF production of the fibroblasts for 45 days. The quantity of PLGA on each microsphere was the following set: {10ng / mg, 100ng /mg, 300ng /mg, 600ng / mg, 1000ng / mg}. PLGA microspheres unincorporated into nanoscaffolds and saline solution (PBS – phosphate buffered saline) were used as controls.	After 45 days the most PDGF had been produced by the fibroblasts with the scaffolds containing 300ng /mg of PLGA on each microsphere (p<0.05). PDGF production quickly tailed off in the unincorporated microspheres.	Nano-fibrous scaffolds containing PLGA microspheres can induce the production of the PDGF growth factor in fibroblasts. The incorporation of PLGA microspheres into a scaffold significantly reduced their degradation.	Wei G et al., 2006 [13]
Nanofibers	PLGA, glucophage, and collagen were dissolved in 1,1,1,3,3,3hexafluoro-2propanol and were spun into nanofibrous membranes.	In vivo and in vitro model (In vitro model to measure collagen release). In vivo model: Diabetic rats were given 8mm wounds. Wounds treated with either active nanoscaffold, empty nanoscaffold or a plain gauze.	Wound closure of the active nanoscaffold group was significantly greater than the gauze group and empty scaffold group after 7 days and greater than the gauze group after 14 days (p<0.05).	A nanoscaffold containing factors required for healthy collagen production will induce greater re-epithelisation, collagen production and wound healing in diabetic rats.	Lee CH et al., 2015 [14]
Nanofibers	Poly (caprolactone) (PCL) / gelatin nanofibrous composite scaffold containing silicatebased bioceramic particles (Ca7P2Si2O16).	In vivo and in vitro (in vitro used to analyse vascular generation properties of scaffold on human epithelial cells). In vivo model: Diabetic mice were given 8mm wounds. Wounds were treated with either PCL, PCL composite nanoscaffolds or nothing.	The CD31 count was significantly greater in the nanoscaffold group than the other two groups throughout the 15 days of the in vivo study (p<0.001). The level of TGF (alpha and beta) and IL-1 was also significantly lower within the nanoscaffold group throughout the 15 days of the study (p<0.001).	The use of silicon ions in a nanoscaffold can significantly upregulate the proliferation of cells required for helaing in a diabetic wound, as well as significantly downregulating pro-inflammatory factors.	Lv F et al., 2017 [15]
Nanofibers	Curcumin incorporated into chitosan nanoparticles and impregnated into a collagen nanoscaffold.	In vivo and in vitro (in vitro to measure curcumin release of scaffold.) In vivo model: Diabetic rats were given 400mm2 wounds. The wounds were treated with either a sterile gauze, a scaffold without curcumin or a curcumin scaffold. Inflammation was also measured during the time period by measuring heat levels.	Wound contraction in the active nanoscaffold group was significantly greater than the other 2 groups after 3 and 7 days (p<0.05) and significantly greater than the other two groups after 11 and 15 days (p<0.01). Heat flow was also reduced in the active nanoscaffold group.	Curcumin application via a nanoscaffold can enhance anti-inflammatory effects and duration, especially in the later stages of wound healing.	Karri VV et al., 2016 [16]
Nanofibers	Curcumin loadedpoly (3-hydroxy butyric acid-co-3hydroxy valeric acid) (PHBV) nanofibers (fabricated via electrospinning)	In vitro model: 0.1, 0.3, and 0.5 % curcumin nanofibers, saline solution and an empty nanoscaffold were all added to mouse fibroblast cells and the % of viable cells was measured after 72 hours.	There was no statistical difference in cell viability between the 5 groups after 72 hours (p<0.01), although a slight increase in cell number was observed with increasing curcumin concentration.	There is negligible cytotoxicity of curcumin laced nanoscaffolds on fibroblasts and there is a slight positive trend in viability with increasing curcumin concentration.	Mutlu G et al., 2018 [17]
Nanofibers	Curcumin-loaded poly (εcaprolactone) (PCL) / gum tragacanthin (GT) nanofibers (fabricated via electrospinning)	In vivo and in vitro. In vitro model: Nanoscaffolds containing curcumin were added to populations of the bacteria MRSA (methicillin resistant staphylococcus aureus) and ESBL (extendedspectrum beta-lactamase producing E. coli). The rate of bacteria growth was compared to a control (untreated bacter ial populations). In vivo model: Diabetic rats were given 10mm diameter wounds. The wounds were treated with either empty or cell lined scaffolds.	In vivo model: The curcumin laced nanoscaffold demonstrated antibacterial growth restrictions of 99.9% against MRSA and 85.14% against ESBL. In vitro model: The curcumin nanoscaffold induced significantly greater healing than the control throughout the investigation and greater healing than the acellular scaffold after 10 and 15 days (p<0.05).	The application of curcumin laced nanofibers may improve the efficacy of antimicrobial compounds as well as significantly increasing the rate of healing of the diabetic wound by regulating the release of the anti-inflammatory compound curcumin.	Ranjbar-Mohammadi M et al., 2016 [18]
Nanofibers	rhPDGF-loaded PLGA membrane laced nanofibers (fabricated via electrospinning)	In vivo and in vitro (in vitro model used to determine structural integrity of scaffolds). In vivo model: Diabetic rats were given wounds of 8mm in diameter. The wounds were treated with either rhPDGF-loaded nanofibrous membranes, PLGA only membranes or an empty gauze.	The active nanoscaffold significantly reduced the wound area compared with the other two groups throughout the investigation: at days 3, 7 and 14 (p<0.05).	A PDGF laced nanoscaffold can continue to release the pro-healing factor PDGF throughout the healing process of a diabetic wound. thereby significantly increasing the healing rate.	Lee CH et al., 2015 [19]
Nanofibers	A nanofibrous matrix composed of ECM (extracellular matrix) componential collagen polycaprolactone (PCL), and bioactive glass nanoparticles (BGNs).	In vivo model: Diabetic rats were given wounds of 2cm in diameter. Wounds were treated with either the active nanoscaffold or a mixture of PCL and ECM collagen or were not treated at all. The wound healing rate was measured for 21 days and the CD31 count was also measured in order to determine the rate of revascularisation.	The active nanoscaffold produced a greater rate of healing between days 4 and 21 than the other two models (p<0.05). CD31 count was also significantly greater in the nanoscaffold group throughout the investigation (p<0.05).	The nanofibrous matrix significantly enhanced cell proliferation and angiogenesis in the diabetic wound. This is most probably via the VEGF pathway.	Gao W et al., 2017 [20]
Nanofibers	rhEGF nanoparticles emulsified with poly (lactic-coglycolic acid) to create a nanoscaffold.	In vivo model: Diabetic rats were given a wound 1.8cm in diameter. The wounds were then treated with either rhEGF nanoparticles, an rhEGF solution, empty nanoparticles or saline solution. Healing rate (primitive area – nonhealing area / primitive area) was then calculated.	The healing rate of the rhEGF nanoparticles was significantly greater than the saline and empty nanoparticles after 7 and 14 days and also significantly greater than the rhEGF solution after 21 days (p<0.01).	A nanoscaffold containing rhEGF is a particularly efficacious method for the treatment of diabetic wounds, especially in their later, post-inflammatory stages.	Chu Y et al., 2010 [21]
Nanofibers	Desferrioxamine (DFO) added to PVA-CS (poly (vinyl alcohol) / chitosan) hydrogel nanofibrous scaffolds.	In vitro and in vivo model (the in vitro model determined the mechanism of action of DFO scaffolds). In vivo model: Diabetic rats were given a wound of diameter 15 mm. The wounds were treated with either DFO hydrogel scaffolds or just hydrogel solutions.	The nanoscaffold group demonstrated a significantly reduced wound area than the hydrogel group between days 6 and 18 (p<0.01).	The Fe2+ chelator DFO scaffolds upregulates the expression of Hif (Hypoxia inducible factor) 1 α, and therefore VEGF, thereby increasing the rate of revascularisation and wound healing.	Chen H et al., 22
Nanofibers	Silk fibroin (from silkworms) was added to rhEGF, PVA (poly (vinyl alcohol) and FGF and then electrospun to create a nanoscaffold.	In vivo model: Diabetic rabbits were given wounds 12mm in diameter. The wounds were then treated with nanoscaffolds composed of silk fibroin from 3 different species of silkworm (Antheraea assama, Bombyx mori, Philosamia ricin) as well as a nanoscaffold without silk fibroin and a saline control.	The silkworm nanoscaffolds induced a significantly greater rate of wound closure than the controls for the first 14 days, with the Bombyx mori scaffold significantly less efficacious in this period. However, by 21 days after the wounds were made, there was no significant difference in wound area between all the nano scaffold groups, although the saline control wound was still significantly behind in terms of closure (p<0.05).	The silk fibroin enhanced scaffolds may significantly improve the rate of diabetic wound closure in the early stages of healing, thereby suggesting that they may have antiinflammatory properties.	Chouhan D et al., 2018 [23]
Nanofibers	Nanofibers carrying the bacterial inhibitor gentamicin sulfate (GS) and recombinant human epidermal growth factor (rhEGF)	In vivo model: Diabetic mice were given a wound of diameter 15mm. The wounds were then treated with one of the following: 1. Saline, 2. 0.1% GS solution, 3. Empty nanoscaffold, 4. Nanoscaffold with both GS and rhEGF or 5. A nanoscaffold with GS but without rhEGF.	The nanoscaffold containing both GS and rhEGF exhibited significantly greater wound closure after 4 days than all other treatments, although at 12 days this it was no better than the GS solution. The two active nanoscaffolds and the GS solution exhibited greater wound closure than saline and the empty scaffold throughout the investigation (p<0.01).	The rhEGF in the nanoscaffold is responsible for increased wound healing in the initial stages of the healing process.	Dwivedi C et al., 2018 [24]
Nanofibers	Poly(ether)urethane– polydimethylsiloxane / fibrinbased scaffold containing PLGA nanoparticles with themselves containing VEGF and FGF.	Diabetic mice were given wounds 8mm in diameter. The wounds were then treated with either saline, the active nanoparticle scaffold, an empty scaffold or a scaffold with growth factors but no nanoparticles.	Throughout the investigation there was no significant difference between the active nanoparticle scaffold and the growth factor scaffold, with the growth factor scaffold inducing slightly increased wound healing. However, at day 15 there was significant difference between these two groups and the two control groups (p<0.01).	The application of scaffolds containing growth factors to a diabetic wound can induce significant fibroblast proliferation and increased wound healing.	Losi P et al., 2013 [25]
Nanofibers	PLGA–collagen hybrid nanofibers containing rh-PDGF.	Diabetic rats were given wounds 5mm in diameter. The wounds were then treated with either a PLGA solution, a collagen solution or the active rh-PDGF nanoscaffold.	Throughout the 14 days of the investigation, the PDGF nanoscaffold significantly reduced the wound area when compared with the two control groups (p<0.05).	The PDGF nanoscaffold increases the rate of diabetic wound healing by increasing the amount of collagen in the wound.	Lee CH et al., 2016 [26]
Gold nanoparticles	Gold nanoparticles, epigal-locatechin gallate and alpha lipoic acid (AuNP+EGCG+ALA)	In vivo model: Diabetic mice were given wounds 1cm in diameter. Wounds were treated with either EGCG, ALA, EGCG & ALA or the AuNP composite. The wound area and the expression of proinflammatory factor RAGE (receptor for advanced glycation end products) were measured for 7 days after injury.	Wound area was significantly lower for the gold nanoparticle composite after 7 days (p<0.01). RAGE expression was also significantly lower for the gold nanoparticle composite after 7 days (p<0.01).	The gold nanopar-ticle composite significantly increases the rate of diabetic wound healing via antiinflammatory and angiogenic properties.	Chen SA et al., 2012 [27]
Gold nanoparticles	Gold nanoparticles, epigallocatechin gallate and alpha lipoic acid (AuNP+EGCG+ALA) – injected via a N2 gas carrier	In vivo model: Diabetic mice were given wounds 1cm in diameter. Wounds were treated with EGCG, ALA, AuNPs or AuNP+EGCG+ALA. The factors were applied to the wounds via a gas carrier each day for 7 days.	Wound area was significantly lower for the gold nanoparticle composite after 7 days until the end of the investigation (p<0.01).	The use of a gas carrier enhances the ability of AuNPs to produce collagen and hyaluronic acid, thereby increasing the rate of wound healing in diabetic subjects.	Huang YH et al., 2014 [28]
Gold Nanoparticles	Gold nanoparticles embedded in a silica (SiO2) matrix: (SiO2@AuNPs)	In vitro and in vivo models (the in vitro model showed that the AuNPs can induce the proliferation of mouse fibroblasts). In vivo model: Rats were given wounds of 2cm in diameter. The wounds were treated with either the gold nanoparticle matrix or a positive control of rh-FGF.	The level of hydroxyproline was higher in the rh-FGF between days 7 and 10, although by day 21, the gold NP matrix treated wounds contained significantly more hydroxyproline (p<0.05).	Gold nanoparticles embedded in a silica matrix can increase the proliferation of fibroblasts and therefore increase the production of collagen in the diabetic wound.	Li X et al., 2015 [29]
Liposomes	SDF-1 (Stromal cellderived Factor 1) embedded into liposomes.	In vivo model: Diabetic mice were given wounds 1cm by 1cm in size. The wounds were then treated with either 100µL of saline with 1µg SDF-1, 100µL of saline with 0.88µg of SDF-1 liposomes, 100µL of saline with 1µg of empty liposomes or 100µL of saline. The wound closure percentage (1 •remaining open wound area / initial wound area) was then calculated.	For the first 14 days and for day 28 there was no significant difference in wound closure between the active liposomes and the saline control. However, at day 21 the SDF-1 liposomes induced a significantly greater wound closure percentage (p<0.05).	In the later stages of wound healing, SDF-1 bound to liposomes may have a positive effect on wound closure. However, this link is not heavily substantiated.	Olekson MA et al., 2015 [30]
Liposomes	Epidermal growth factor (EGF), insulin-like growth factor-I (IGF-I), and platelet-derived growth factor-A (PDGF-A), all combined with protamine and hyaluronic acid and fused into liposomes.	In vivo model: Diabetic mice were given wounds 8mm in diameter. The wounds were then treated with either empty liposomes, liposomes with each of the growth factors at a concentration of 100µg /ml or liposomes with each of the growth factors at a concentration of 20mg / ml. The wound area was then measured for 11 days.	On days 1,3,9 and 11 the higher dose of growth factors significantly reduced wound area with p<0.001 and on day 7 the higher dose of growth factors significantly reduced wound area with p<0.01 when compared with the empty liposome control. After 11 days the lower dose of growth factors significantly reduced wound area when compared with the empty liposome control	The combination of several growth factors, alongside hyaluronic acid can significantly reduce wound area in diabetic patients by upregulating fibroblast proliferation and, therefore, collagen production.	Choi JU et al., 2017 [31]