76.2.2. Non-Metallic
There are numerous inorganic non-metallic antibiofilm variants. Metallic quantum dots (QD) can create a hassle in terms of toxicity. A better biocompatible substitute is the use of carbon QDs
[173][78], which are arranged carbon QDs in self-healing hydrogels with anti-inflammatory and wound-healing benefits. They were studied as an injectable to hinder
S. aureus and
E. coli biofilms and enhance full-thickness wound healing. Additionally, they were relatively better at inhibiting mature
S. aureus biofilms than gentamicin. The inference suggests the mechanism to be due to the cationic activity of the QD and its low drug resistance
[174][79]. Other forms of carbon, such as fullerene, are also potent wound infection eliminators. Researchers have designed a fullerene NP that is functionalized with sulfur to terminate the MDR
P. aeruginosa biofilm isolated from clinical chronic wounds, in order to explore the ascendary of the NP over the expression of toxA gene, which is encoding for exotoxin A, an important virulence factor of the strain. It reduced the gene expression
[175][80].
7. Nanotechnology in Regeneration
8.1. Intrinsic Regenerative Properties
7.1. Intrinsic Regenerative Properties
There are endless designs derived from nanotechnology. Nanoscale architecture helps in remodeling its microenvironment and liberating healing benefits to an injury. Interestingly, scholars have shed light on purposing nanotopography as a cell-aligning agent at the wound site
[181][81]. The system was integrated with a microfluidic setup to which the nano-engraved patterns were aligned in parallel and perpendicular directions. This was used as a biomimicking profile of collagen fibers and fibroblasts to cue the swift migration of NIH-3T3 fibroblast cells to the wound site. The nanopattern that lay perpendicular to the microchannel of the setup displayed a speedy recovery due to collective migration guided by the nanotopography. Thus, the intrinsic capability of nanoengineered materials offer limitless sophisticated approaches to the remodeling of an injury.
8.2. Transdermal Nanocarriers
7.2. Transdermal Nanocarriers
The use of transdermal drug deliveries is one of the recent and attractive methods that have a very convenient application, fewer systemic side effects and a less-pass effect. Due to its non-invasive properties, the transdermal carriers demonstrate the highest clinical potential, with very high drug delivery efficiency
[187][82].
For an ideal shipment system, it is crucial to have a nontoxic vehicle that protects therapeutic integrity and increases its access to the injured site
[188][83]. For instance, thrombin is an important tissue repair essential
[189][84]. Conjugating magnetite (γ-Fe
2O
3) NP with thrombin is a means to expand its bioavailability without compromising its therapeutic value. In addition, the in vivo wound response on treatment with the conjugated NP resulted in heightened tensile strength. That, in turn, is essential for reducing wound dehiscence compared to treatment with free thrombin
[190][85].
8.3. Nano Scaffold Tissue Engineering
7.3. Nano Scaffold Tissue Engineering
Molding the topography at a nanoscale paves the way to directional remodeling of an injured site. The directional movement was put to test using uniformly spaced nanoscaffolds. The spaces were defined as dense (300–400 nm), intermediate (500–600 nm) and sparse (700–800 nm) based upon an increasing width range
[203][86]. In an in vitro wound model, the healing trend displayed a direct correlation of fibroblast migration with dense nanotopography.
Bioengineered alternatives in wound care offer a plethora of substitutes, processes and conjugates. This makes them an enormous economic healthcare resource. Stem cell-based therapy facilitates the re-epithelialization of cutaneous wounds and boosts angiogenesis
[204][87]. Delivery of mesenchymal stem cells at the site of the wound can result in its fastened cell death. Biomimetic delivery vehicles can overcome this challenge
[205][88]. The engineered nanofiber-stem cell serves as an efficient mode for promoting wound healing. The bio nanocomposite was framed with mesenchymal stem cells derived from bone marrow that are functionalized over nanofiber scaffolds, demonstrating an escalated epidermal differentiation of burn wounds
[206][89].
8.4. Nanotopography in Prevention of Biofilm
7.4. Nanotopography in Prevention of Biofilm
The topography of the surface greatly influences the development of biofilm by the sessile microbial colonies
[234][90]. Various studies have demonstrated that the adhesion of the bacterial cells to a surface varies greatly with the change in the topography. Effective contact angle and surface hydrophilicity or hydrophobicity are key factors in the mechanism of the development of biofilm. The nanostructured materials prevent the adherence of the cells by setting off physicochemical changes, resulting in the development of cell deformation. The topographic changes brought about by nanostructures also develop gradient changes that prevent the adherence of the cells
[234][90]. Studies have revealed that both 3D and 2D nanostructures have played an important role in the mechanism of inhibiting the development of biofilm. The 2D nanomaterials help in inhibiting the effective surface area of contact and air entrapment, thereby preventing the biofilm development on the biotic and abiotic surfaces. TiO
2 NP and nanopillars help in the prevention of the development of biofilm
[235][91].
8. Intelligent Nanotechnology
9.1. Wound Healing
8.1. Wound Healing
98.1.1. Physically Responsive Nanomaterials
The use of thermo-responsive and photo-responsive nano therapy may lead to an uneven targeting of Gram-positive and Gram-negative bacteria. Coupling the two has proven to enact faster wound closure.
98.1.2. Chemically Responsive Nanomaterials
One of the environmental cues come from the fact that bacterial wound infestations create alkaline ambience. The pH of the wound bed needs to be considered while framing remedial dressings for chronic wound infections
[250][92]. This pH is also indicative of bacterial proliferation
[253][93]. Pathological conditions, such as diabetes and venous leg ulcers, can impair angiogenesis
[254,255][94][95].
98.1.3. Bio-Responsive Nanomaterial
The usage of wound site facilities improvises the treatment processes. The generation of ROS at wounds orchestrates the healing cascade and may also result from an infection at the plot
[257][96]. The development of ROS-reactive nanomaterials ensures the targeted release of wound-healing stimulants. One such example is that of the ROS-responsive nanomaterial poly-(1,4-phenyleneacetone dimethylene thioketal) loaded with the stromal cell-derived factor-1α (SDF-1α). Subsequently, the release of SDF-1a from the NPs stimulates a chemotaxis of bone marrow MSCs at the wound site. This recruitment was demonstrated among full-thickness skin wounds of mice and resulted in wound vascularization and accelerated healing
[258][97].
9.2. Anti-Microbial Wound Care
8.2. Anti-Microbial Wound Care
The mechanism of bacterial colonizations can act as breeding grounds for intelligent wound care. The best proposal is to deliberately utilize the by-products of a pathogenic bacterial invasion, thereby framing “smart” wound dressings that act upon interaction with microbial prospects.
α-toxin, secreted by
S. aureus, drills pores to impair cellular membranes. This virulence is incorporated in a liposome-based nanoreactor to ward off MDR bacteria. The components of the nanoreactor were calcium peroxide and rifampicin, which are then coated with lecithin and DSPE-PEG3400. Upon their interaction with a pathogenic environment, the a-toxins pierce through the nanoreactors. The pores then drown the nanoreactor with water, releasing hydrogen peroxide upon reaction with calcium peroxide. The decomposition of the H
2O
2 buds off oxygen, which liberates rifampicin. This smart nano system staged an anti-MRSA impact on the in vitro mode, alongside a significantly higher wound closure rate in the in vivo mode
[259,260][98][99]. Apart from utilizing virulence, the enzyme-responsive bactericidal nano agents are also potent ammunition. This is based upon the secretion of hyaluronidase from pathogens as instigators for the nano agent
[261][100]. On that note, for the development of a chemo-photothermal nano system to annihilate MDR bacteria, hyaluronic acid (HA) was preliminarily coated on ascorbic acid (AA), then the drug formulation was loaded in a mesoporous ruthenium NP. The nanocarrier was then mounted by catalyst—the ciprofloxacin-coated molybdenum disulphide (MoS
2). On reaching the infection site, bacterial hyaluronidase decomposed the HA and subsequently liberated the AA that generated the in situ hydroxyl radicles by the MoS2 catalysis. This antibacterial strategy was increased by being accompanied with the photothermal nature of Ru NPs. Further, the AA@Ru@HA-MoS
2 nanosystem was investigated against a skin-infected model. The results not only showcased the accelerated healing of the wound but also inhibited the formation, growth and multiplication of biofilms
[262][101].
109. Advanced Nanotechnology
10.1. Wireless Monitoring
9.1. Wireless Monitoring
The upliftment of point-of-care wound monitoring requires hassle-free access to the injury-dependent factors. This is devised by either monitoring the microbial intensity or the wound in situ changes. This foresight in the wound care set-up can improvise the prompt healing of skin injuries. The detection accuracy is modified with the assistance of intelligent NPs to wirelessly indicate the physiology at wound site. Such a wireless-mediated outlook mostly employs a color-changing apparatus. For instance, antimicrobial agents with lipid vesicles were implanted in UV-photocrosslinkable methacrylated gelatin. The vesicles contained self-quenching fluorescent dyes resulting in a calorimetric indication upon interplay with infection. The toxins/enzymes secreted by
P. aeruginosa and
S. aureus disrupts the membrane bilayer of lipid vesicles, resulting in the expulsion of antimicrobials with a visual color alteration in the microenvironment
[265][102]. Similar strategies were taken against the detection of wound biofilms with the help of intelligent WDs
[266][103]. Researchers have designed a pH-responsive fluorescence scheme in a rabbit
S. aureus wound model and terminated the biofilm presence with simultaneous imaging of the same. Such detection is critical, as it governs the success of the nanosystem in wound healing by an accompanying monitoring strategy
[267][104].
The remote supervision of the state of healing dispatches easy and rapid diagnosis for the medical staff and the wounded victim. Real-time monitoring by wireless communication technology revolutionizes WD to a “smart” WDs
[268][105]. The substrate-integrated circuit is the key to flexible surveillance of an injury. It has been reported that the combination of a biomimetic nanofiber membrane, a microenvironment sensor and a gelatine methacryloyl (GelMA)- β-cyclodextrin (β- cd) UV-crosslinked hydrogel is an integrated smart dressing. The dressing promotes angiogenesis and wound healing with instantaneous monitoring. While the GelMA -β- cd UV-crosslinked hydrogel boosts reformation
[269[106][107][108],
270,271], an integrated-chip supervises the wound microenvironment via transmission of data to a Bluetooth low-energy (BLE) 4.0 antennae on a smartphone mediated customized app
[272][109]. Wound telemonitoring may encompass a wireless magnetic sensor using calor as a biomarker to develop smart WD technology
[273][110].
The expansion of mobile surveillance of wound is infinite given the countless combinations of nanoscale operations from which to choose. One of them are the peroxide-sensing single-walled carbon nanotubes (SWCNTs) fabricated as wearable textiles
[274][111]. The nanotubes were encapsulated within a polymer shell and soluble in organic solvent, enhancing its biocompatibility. This nanocomposite demonstrated a shift in NIR fluorescence in detecting physiologically relevant levels of peroxide in wounds. A differential response to hydrogen peroxide results from different bandgap energies of SWCNTs. The spectral attribute arises from their variable DNA sequence and chirality, as a response to the local environment
[275,276][112][113].
10.2. Artificial Intelligence
9.2. Artificial Intelligence
Artificial intelligence (AI) can also be integrated into the functioning of nanoparticle-based dressings
[278,279][114][115]. AI avails of health benefits by automated learning and proctoring myriads of clinical records for manging wound care decision making with predictive data
[280][116]. Deep learning algorithms, such as the convolutional neural network (CNN), require low pre-processing time for differentiating input images
[281][117]. This creates an advantageous mechanism for the automated detection of biofilms. In a rhinology diagnostic support study, a CNN-based biofilm scanning system results in an accuracy of ~98%, granting swift identification of biofilm in the images
[282][118]. Existing machine learning also partakes in detection of biofilms. Machine learning and quantitative structure-activity relationship (QSAR) models predict the performance of different quorum-sensing compounds. This system accesses the trajectory of the range of effectiveness of the compounds across a biological setup, thus encouraging the intuitive design of countering biofilms
[283][119]. Under similar contexts, AI can be replicated across platforms for monitoring cutaneous injuries. For example, it can be used as a diagnostic tool to aid the experts in evaluating the condition of the wound. Although there can be errors in the system, they can be escaped with the progression of the tool
[284][120]. Combining AI with nanotechnology is a leap forward towards better health care.
There are immeasurable resources waiting to be discovered in the form of AI-nanoconjugate synergy. Volatile organic compounds (VOCs) are potential biomarkers for the diagnosis and surveillance of diabetic wounds
[285][121]. Researchers have devised an ultra-selective detection of volatile organic compounds (VOCs) via an AI-nanomaterial sensor system. The system uses a modified Si nanowire field effect transistor (SiNW FETs) that is functionalized with varied saline molecules for the classification of VOCs. The model enables the selective detection of gas-phased chemical components in single component as well as a multicomponent environment. When conjugating an artificial neural network (ANN) model, the sensors were capable of recognizing 11 VOCs and retained its efficiency upon physical/chemical interferences. This enacts a beaming prospect to detect VOCs in wounds
[286][122].