Med Lasers 2024; 13(2): 75-81  https://doi.org/10.25289/ML.24.016
Advances in laser and stem cell treatment: current technologies, limitations, and future prospects
Seung Hoon Woo
Department of Otorhinolaryngology-Head and Neck Surgery, Dankook University College of Medicine, Cheonan, Republic of Korea
Correspondence to: Seung Hoon Woo
E-mail: lesaby@hanmail.net
ORCID: https://orcid.org/0000-0001-7560-1140
Received: June 15, 2024; Accepted: June 24, 2024; Published online: June 30, 2024.
© Korean Society for Laser Medicine and Surgery. All rights reserved.

This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Recent advances in medical technology have seen the convergence of laser and stem cell treatments, promising unprecedented therapeutic outcomes. This review explores the current state of laser and stem cell therapies, examining the underlying mechanisms, clinical applications, limitations, and future directions. Despite substantial progress, several challenges remain, such as precise targeting, treatment efficacy, and long-term safety. This paper highlights the synergistic potential of combining laser and stem cell therapies and proposes pathways for future research to address the existing gaps and enhance clinical effectiveness.
Keywords: Laser therapy; Stem cell; Therapeutic; Regenerative medicine
INTRODUCTION

The intersection of laser and stem cell treatments represents a burgeoning frontier in regenerative medicine. Laser therapy has long been utilized for its precision and minimally invasive nature, while stem cell therapy holds promise for repairing and regenerating damaged tissues. The integration of these technologies aims to enhance therapeutic outcomes and address unmet medical needs.

LASER THERAPY: MECHANISMS AND APPLICATIONS

Mechanisms of action

Laser therapy operates on principles of photobiomodulation, where specific wavelengths of light interact with biological tissues to induce cellular responses. These responses include increased ATP (adenosine triphosphate) production, enhanced cellular proliferation, and modulation of inflammatory processes (Fig. 1) [1,2].

Figure 1. Signal pathways involved in low-level laser therapy/treatment (LLLT)-induced cell mechanisms. TPKR, tyrosine-protein kinase receptors; PI3K, phosphoinositide 3-kinases; Akt, protein kinase B (PKB); eNOS, endothelial nitric oxide synthase; mTOR, mammalian target of rapamycin; Ras, rat sarcoma virus; Raf, rapidly accelerated fibrosarcoma; MEK, mitogen-activated protein kinase kinase; ERK, extracellular signal-regulated kinase; MnK1, MAP kinase interacting kinase 1; elF4E, eukaryotic initiation factor 4E; PLC, phospholipase C; DAG, diacylglycerol; IP3, inositol triphosphate; PKC, protein kinase C. Reused from the article of Woo and Abueva (Med Lasers 2022;11:134-42) [1].

Clinical applications

Laser therapy is widely used in various medical fields due to its precision and minimally invasive nature. Here are some key areas where laser therapy has shown significant clinical benefits:

Dermatology

In dermatology, laser therapy is employed to treat a variety of skin conditions, including scars, wrinkles, and vascular lesions. It has proven effective in reducing the appearance of acne scars and improving skin texture and tone [3]. Fractional laser resurfacing, in particular, has been shown to stimulate collagen production and promote skin rejuvenation [4].

Orthopedics

In orthopedics, low-level laser therapy (LLLT) is used to enhance tissue repair and alleviate pain. Studies have demonstrated its efficacy in treating tendinopathies, osteoarthritis, and sports injuries [5,6]. Laser therapy helps reduce inflammation, promote angiogenesis, and accelerate the healing process in musculoskeletal disorders [7].

Oncology

Laser therapy plays a crucial role in oncology, particularly in tumor ablation and photodynamic therapy (PDT). In PDT, a photosensitizing agent is activated by laser light, producing reactive oxygen species that selectively destroy cancer cells [8]. This approach has been used to treat various cancers, including skin, lung, and esophageal cancers, offering a minimally invasive alternative to traditional treatments [9].

Ophthalmology

Ophthalmology has greatly benefited from laser technology, especially in the treatment of retinal disorders and refractive surgeries. Laser photocoagulation is a standard treatment for diabetic retinopathy and macular degeneration, preventing vision loss by sealing leaking blood vessels and reducing abnormal vessel growth [10]. Additionally, laser-assisted in situ keratomileusis surgery has revolutionized vision correction, offering precise and effective refractive error correction [11].

STEM CELL TREATMENT: MECHANISMS AND APPLICATIONS

Stem cell biology

Stem cells possess the unique ability to differentiate into various cell types and self-renew. Embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and adult stem cells each offer distinct advantages and challenges for therapeutic use [12].

Clinical applications

Stem cell therapy has shown promise in treating a range of conditions, with numerous clinical applications demonstrating significant potential for regenerative medicine:

Neurodegenerative diseases

Stem cell therapy offers hope for neurodegenerative diseases such as Parkinson’s disease, Alzheimer’s disease, and amyotrophic lateral sclerosis. Transplantation of neural stem cells has shown potential in replacing lost neurons and supporting neural regeneration. Clinical trials are exploring the use of stem cell-derived dopaminergic neurons for Parkinson’s disease, aiming to restore motor function and improve quality of life [13,14].

Cardiovascular disorders

Stem cell-based therapies have demonstrated potential in treating cardiovascular diseases, including myocardial infarction and heart failure. Intramyocardial injection of stem cells, such as mesenchymal stem cells (MSCs) or iPSC-derived cardiomyocytes, aims to regenerate damaged heart tissue and improve cardiac function. Clinical trials have reported improvements in left ventricular ejection fraction and reduced scar size, highlighting the therapeutic potential of stem cell therapy in cardiology [15,16].

Musculoskeletal injuries

Stem cell therapy has been extensively investigated for musculoskeletal injuries, including cartilage defects, tendon injuries, and bone fractures. MSCs, in particular, have shown promise in promoting tissue repair and regeneration. Intra-articular injection of MSCs has demonstrated positive outcomes in osteoarthritis, reducing pain and improving joint function [17]. Similarly, stem cell-based approaches have shown potential in enhancing tendon healing and accelerating fracture repair [18,19].

Hematopoietic disorders

Hematopoietic stem cell transplantation (HSCT) has long been a standard treatment for hematologic malignancies and disorders. HSCT involves the transplantation of healthy hematopoietic stem cells to restore normal blood cell production in patients with conditions such as leukemia, lymphoma, and aplastic anemia. Advances in stem cell sources, conditioning regimens, and graft manipulation techniques have significantly improved outcomes and expanded the applicability of HSCT [20,21].

Regenerative section

The field of regenerative medicine aims to restore or establish normal function in damaged tissues and organs. Stem cell therapy is at the forefront of this effort, given the unique capabilities of stem cells to differentiate into various cell types and their potential for tissue repair and regeneration. Laser technology has emerged as a potent tool to enhance the effectiveness of stem cell-based regenerative treatments.

Laser-assisted stem cell therapy leverages the ability of lasers to modulate cellular behavior. For instance, LLLT can stimulate stem cell proliferation and differentiation, thereby enhancing tissue regeneration. This is particularly beneficial in treating chronic wounds, bone fractures, and other conditions where tissue regeneration is crucial. By optimizing the microenvironment and promoting the homing and integration of stem cells, lasers can significantly improve the outcomes of regenerative therapies [22].

Recent studies have demonstrated the efficacy of laser- assisted techniques in bone regeneration. For example, the use of LLLT has been shown to enhance the osteogenic differentiation of MSCs, promoting bone healing and reducing recovery time [23]. Similarly, in cartilage regeneration, laser treatment has been found to improve the proliferation and chondrogenic differentiation of stem cells, aiding in the repair of cartilage defects [24].

Furthermore, lasers can be used to precondition stem cells before transplantation. This preconditioning enhances the survival and functional integration of the transplanted cells, leading to better regenerative outcomes. Laser preconditioning has shown promising results in improving the therapeutic potential of stem cells in various regenerative applications, including myocardial infarction and liver regeneration [25].

The integration of laser technology in stem cell therapy represents a significant advancement in regenerative medicine. By enhancing stem cell proliferation, differentiation, and integration, laser-assisted techniques hold great promise for improving the efficacy of regenerative treatments and addressing unmet medical needs.

Dermatology section (anti-aging)

In dermatology, the pursuit of anti-aging treatments has led to the exploration of various innovative techniques, including the use of lasers and stem cells. The synergistic application of these technologies offers promising avenues for skin rejuvenation and the treatment of age-related skin conditions.

Laser therapy is widely recognized for its ability to improve skin texture and tone, reduce wrinkles, and promote collagen production. Fractional laser resurfacing, for instance, creates microthermal zones in the skin, stimulating the body’s natural healing processes and leading to the formation of new collagen. This results in smoother, more youthful-looking skin [3].

When combined with stem cell therapy, the anti-aging effects of laser treatments can be significantly enhanced. Stem cells have the potential to regenerate damaged skin cells and promote the production of essential extracellular matrix components such as collagen and elastin. By incorporating stem cells into laser treatments, it is possible to achieve more substantial and longer-lasting anti-aging results [26].

Clinical studies have demonstrated the effectiveness of combining laser therapy with stem cell treatments in dermatology. For example, the application of LLLT in conjunction with stem cell-based creams or serums has shown to accelerate skin healing, reduce inflammation, and enhance skin regeneration. This combination therapy has been effective in reducing fine lines, improving skin elasticity, and treating photodamage [27].

Moreover, stem cell-conditioned media, which contains a rich array of growth factors and cytokines, can be used in conjunction with laser treatments to further enhance skin rejuvenation. This approach leverages the regenerative properties of stem cells without the need for direct stem cell transplantation, making it a less invasive yet effective anti-aging treatment [28].

The integration of laser and stem cell technologies in dermatology offers a powerful approach to combat aging and improve skin health. By combining the rejuvenating effects of lasers with the regenerative potential of stem cells, these advanced therapies provide a promising solution for achieving youthful, healthy skin.

SYNERGISTIC POTENTIAL OF LASER AND STEM CELL THERAPIES

Enhancing stem cell efficacy with lasers

Combining laser therapy with stem cell treatments can potentially enhance the survival, proliferation, and differentiation of transplanted cells. Laser preconditioning of stem cells has been shown to improve their regenerative capabilities [29]. For instance, LLLT can enhance the proliferation and differentiation of MSCs, promoting tissue repair and regeneration in conditions such as chronic wounds and tendon injuries [30].

Case studies and clinical trials

Several studies have reported improved outcomes in wound healing and tissue regeneration when combining these therapies. For example, laser-assisted stem cell therapy has demonstrated accelerated healing in chronic ulcers and orthopedic injuries [18]. In a clinical trial, the combination of LLLT and stem cell therapy resulted in significant improvements in wound closure and tissue regeneration in patients with diabetic foot ulcers [19]. Another study reported enhanced bone healing and reduced healing time in patients with tibial fractures when treated with a combination of laser therapy and MSCs (Fig. 2) [7,31].

Figure 2. Schematic representation of the application of photobiomodulation (PBM) on stem cell and therapeutic benefits. PBM using wavelengths from the red to near-infrared light spectrum (600 to 1,000 nm) induces mesenchymal stem cell proliferation and differentiation for tissue engineering and regenerative medicine. hASC, human adipose stem cell; hUCMSCs, human umbilical cord blood-derived mesenchymal stem cells; hDPSC, human dental pulp stem cell; hBMMSCs, human bone marrow mesenchymal stem cells. Reused from the article of Chang et al. (Med Lasers 2020;9:134-41) [31].
CURRENT LIMITATIONS

Precision and targeting

Despite advancements, precise targeting of laser treatments remains challenging. Achieving optimal dosimetry and minimizing damage to surrounding tissues are ongoing concerns [32]. Additionally, the heterogeneous nature of stem cell populations and variability in cell delivery methods pose challenges in achieving consistent therapeutic outcomes [33].

Stem cell viability and integration

Ensuring the viability and proper integration of stem cells in host tissues is another significant hurdle. Issues such as immune rejection and uncontrolled differentiation pose risks [34]. Moreover, the potential for tumorigenicity with certain stem cell types, particularly iPSCs and ESCs, necessitates rigorous safety evaluations and monitoring [35].

FUTURE DIRECTIONS

Technological innovations

Future research should focus on developing more sophisticated laser delivery systems and enhancing stem cell engineering techniques. Innovations such as nanotechnology and bioengineering hold promise for improving therapeutic precision and efficacy [36]. For example, nanoparticle-mediated laser therapy could enable targeted and controlled release of therapeutic agents, enhancing the therapeutic effects while minimizing side effects [37].

Personalized medicine

Advances in genomics and biotechnology will enable more personalized approaches to treatment, tailoring therapies to individual patient needs and genetic profiles [38]. Personalized medicine approaches can optimize stem cell selection, genetic modification, and laser parameters to achieve the best therapeutic outcomes for each patient [13].

Regulatory and ethical considerations

As these technologies advance, regulatory frameworks must evolve to ensure safety and efficacy. Ethical considerations, particularly concerning stem cell use, require ongoing dialogue and consensus [33]. Establishing standardized protocols and guidelines for stem cell processing, characterization, and clinical application is crucial for advancing the field and gaining regulatory approval [14].

CONCLUSION

The convergence of laser and stem cell therapies heralds a new era in regenerative medicine. While significant progress has been made, overcoming current limitations and harnessing future innovations will be crucial for realizing the full potential of these therapies. Continued interdisciplinary research and collaboration will drive this field forward, offering hope for more effective and personalized medical treatments.

SUPPLEMENTARY MATERIALS

None.

ACKNOWLEDGMENTS

None.

AUTHOR CONTRIBUTIONS

All work was done by SHW.

CONFLICT OF INTEREST

No potential conflict of interest relevant to this article was reported.

FUNDING

None.

DATA AVAILABILITY

None.

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